Mermaid Cake Recipe
This buttercream mermaid cake is perfect whether it’s a little girl’s birthday party or an adult mermaid party!. This tall buttercream cake with the mermaid tail toppers and fondant accessories will steal your heart. With my step-by-step and video tutorial, you can make this for your little princess too.

This year, I made this mermaid birthday cake for Rhea’s birthday. She loves swimming very much and we always say she swims like a mermaid. So, of course, she is fascinated with mermaids.
I also made this a double barrel cake, as you can see. These are two cakes stacked as one. This time, I decided to do a buttercream finish instead of covering the cake in fondant.
I thought it would make a lovely tutorial, so I hope you find it useful. The video is detailed. So, feel free to skip parts that you find not relevant to your project.
Why make a little mermaid cake
- It is a simple and easy cake, but it does need some preparation and time management.
- There are three main components to the cake
- Cake – I have given you an oiled-based vanilla cake recipe below, which is light and airy. And yet, you can also use any of my other layer cake recipes.
- Frosting – It’s summer, so I am using my velvet American buttercream. But, any other buttercream icing would work just as well. See my list of 30 plus buttercream recipes here.
- Mermaid cake decorations – I’ve made simple free hand-shaped mermaid tails which you can do by watching the video. Alternatively, you can also use silicone molds for the tails, shells, and other ocean-themed decorations. These days you can also find candy shaped like fish, mermaid tails, shells, and other maid theme candy. Be creative!
Cake decorating timeline
- Fondant accessories prep time – 1 hr (need 4 – 6 hrs drying time)
- Bake the cakes – 2 hours
- Cool the cake – 4 hours, preferably overnight
- Prepare buttercream & simple syrup – 30 mins
- Level, torte, fill, and stack cake – 30 to 45 mins
- Frost cake – 45 mins
- Assemble cake – 45 mins

Videos
Tie-dye cake recipe
Mermaid cake tutorials
Mermaid cake Instructions
Cake batter
- Preheat the oven at 165°C/325°F/ Gas Mark 3
- Grease and line with parchment paper 4 x 7-inch round cake pans (or 3 x 8-inch round cake pans).
- Dry ingredients – Combine flour, baking powder, baking soda, and salt – set aside.
- Eggs – In the bowl of a stand mixer with a whisk attachment on medium speed whip the whole eggs for 2 minutes. Gradually add the sugar a little at a time and continue to whip until the eggs are light and foamy or ribbon stage
Pro tip – adding the sugar gradually will prevent the eggs from separating. - Oil – Next, gradually add the oil while whipping continuously.
Pro tip – adding the oil gradually will help the oil emulsify with the eggs similar to mayonnaise. - Combine – Next, add the flour mixture along with the buttermilk and sour cream in three or four batches. Scraping the sides of the bowl when necessary.
Pro tip – Combine the buttermilk and sour cream together – use a whisk to ensure no lumps – set aside.

- Pans – Divide this batter between the four baking pans. I used cake strips to ensure I had flat cakes with no domes.
Note – I divided the batter into 4 bowls and colored each in shades of pink (my daughter’s request was pink inside) before I create a tie-dye kinda effect. - Bake – Place the pans on the middle rack and bake for 30 to 35 minutes or until a skewer inserted in the center comes out clean.
Pro tip – Rotate the pans between baking time (after 20 mins) top to bottom racks and vice versa. - Cool – Once baked, cool in the cake tins on a cooling rack for 10 minutes then invert cakes from the baking pans and cool completely. When cooled, wrap each cake in plastic wrap and let chill in the fridge for at least 4 hours.
Pro tip – keeping the cakes in the pan for longer will make them soggy with the steam. Chilling cakes before frosting makes them easier to handle with fewer crumbs and breakage.

Frosting
- Meringue – In the bowl of a stand mixer with the paddle attachment, combine the meringue powder, heavy cream, and approximately two cups of powdered sugar. Whip starting on low speed until you have a thick, light, and sticky mixture.
Pro tip – we make a meringue first this is what makes this buttercream different from other American buttercream recipes. - Powdered Sugar – Next, gradually start adding the remaining powdered sugar in two batches.
Pro tip – the mixture at the moment will be very dry and crumbly but continue to combine. - Butter – Once all the butter is in – run the mixer on high for about 3 to 5 minutes more. Whip until you have a light and fluffy, creamy velvety texture very similar to whipped cream.
Pro tip – do not skip on the whipping as this is what will give us that whipped cream-like consistency. - Divide – Use 3 cups of buttercream for filling between the layers. The rest can be colored with gel food coloring – I used turquoise, purple, fuchsia, and pink. Place the colored buttercream in piping bags without tips.

Stacking the cake
- Syrup – Prepare simple syrup to moisten the cake layers. These will keep the cake moist for longer.
- Level, moisten – Using a bread knife or cake leveler cut the domes off the cake layers. Brush each layer with the cooled simple syrup.
Pro tip -if you plan to move the cake again, it is best to use a cake circle under the cake, so you can pick the cake with its base and without any accidents. - Two layers – Place a cake layer on the cake board or cake stand. Top with a big dollop of buttercream – spread evenly using a straight-edge spatula. Then top with the second layer.
- Dowel – Next, add 4 dowels in to the cake using the first as a guide to cut the others. Make sure they are straight at 90 degrees so they do not tilt. Then, place the 6-inch cake circle on top. Add a little more buttercream and spread with a spatula.
Pro tip – doweling the cakes will prevent the bottom layers from sinking with the weight of the top layers.

- Next two layers – Then, top the three cake layer on top followed by more buttercream and the next layer.
Pro tip – you need to dowel the cake only if you are using more than 3 layers of cake. 3 layers can be easily stacked without any support. - Frost – Next, pipe the colored buttercreams all around the cake starting with the turquoise at the bottom, followed by purple, fuchsia, and pink.
Note – I wanted the top of the cake to look slightly narrow than the bottom. So, I use a 6-inch cake board as a guide to carve out the top crown. If you watch the video it will make sense. - Smooth – Use a straight-edged spatula to spread the buttercream evenly as well as to marble some of the colors so they blend into each other.
- Pattern – Next, use the tip of a spatula to create lines all around the cake as shown in the video.
- Top – Finally, add more buttercream on top and smooth the top. Smooth it with an offset spatula.
- Chill – Place the cake in the fridge for at least 30 minutes before you assemble it.
Pro tip -chilling will firm the buttercream which makes it easier to place all the edible decorating without a mess.

Mermaid tails, shells, seaweed, seashells
- Divide the fondant into smaller portions and use food gel colors to make different shades that will match the cake.
Pro tip – Add ½ tsp of CMC to the fondant. This will ensure it holds its shape when molded. - Tails – Create three mermaid tails free-hand as shown in the video or you can also use a mermaid tail silicone mold.
- Shells, corals – I used a seashell mold to make the seashells and corals. You can fill it with melted chocolate or use fondant as well.
- Seaweed – Cut strips of fondant in greens for the grass and seaweed.
- Dry – Place everything on a parchment-lined baking tray and let dry completely
Pro tip – these will take 4 to 6 hours but can be made a few days in advance as well.

Assemble
- Decorations – Start by arranging the corals and grass around the cake. Then, add the seashells and the rest of the fondant accessories you created.
Pro tip – these will stick easily on the buttercream so you don’t need any water or edible glue. - Center dowel – Finally, add three skewers on top of the cake and place the mermaid tails on it.
Pro tip – these will hold the weight of the tails and prevent them from sinking into the cake as well as help support the cake with additional support. - Sand – Add all the edible sand ingredients to a bowl and combine well. Spoon edible sand all around the cake and at the base of the mermaid tails.
- Ribbon – Don’t forget to put a ribbon around the cake board. It completes the cake.

Tips for success
- Bake the cakes in advance so they have enough time to cool. Nothing is more frustrating than a melting frosting on a cake.
- There is no need to rush the process. Use the timeline given above to plan the cake. That way you will enjoy the process and do a good job too.
- I am using buttercream frosting that can stay out of the fridge for days but if you use perishable frosting make sure to keep it chilled in the cake.
- If you live in a hot and humid climate use a frosting that will give you enough time to frost, as well as travel to your final destination.
- A cold cake is easier to transport so always chill the cake well before you move it. Fewer accidents happen when the cake is well chilled.
- Don’t make haste. Stand back and look at the cake – see what looks good and where you can add more decorations. Since this is a buttercream cake place things correctly, so you don’t have to move them around.
- You may or may not need all the edible decorations you created, so don’t feel pressured to add it all. Sometimes less is more.

Variations
- Confetti mermaid cake – You can add 1 cup of sprinkles to the cake batter before dividing between the pans to make a confetti cake. Add more sprinkles and dragees to complete the theme.
- White chocolate mermaid cake – use white chocolate buttercream instead of American buttercream to frost the cake.
- Unicorn mermaid cake – I’ve used the ocean colors but you can use unicorn or rainbow colors to accent the buttercream. Try purple, green, and blue food colors.
- Mermaid birthday party – you can also add some mermaid cupcakes topped with mermaid tails alongside this cake. Add a few mermaid party hats and snacks too. Kids’ books are great for inspiration.
- Mermaid chocolate cake – I’m using a white cake but kids love chocolate so use a chocolate cake inside. Crumb coat with white buttercream then continue with the colored buttercream to complete the design.
- Mermaid tail cake – Add another dome cake on top of this cake and shape it like a tail. Attach a fondant mermaid tail at the top.
- Fondant mermaid cake – Frost the cake with a smooth buttercream finish and then cover the cake with your preferred colored fondant. Attach the fondant decorations to the cake with water or melted white chocolate.
Frequently asked questions
This cake will keep at on the counter in cool temperatures for up to 3 days. If you plan to travel with it chill it thoroughly in the fridge before the trip.
The options for cake fillings and frostings are endless. Try bakery-style vanilla or chocolate frosting. Then, there is my eggless vanilla or caramel buttercream. Alternatively, some less sweet alternatively would be the meringue or custard-based frosting such as Swiss, Italian, French, or German frosting.
This should be considered two cakes when cutting. So, the first cake is made with two layers of cake. Once you cut those slices, remove the cake board and dowels below before you cut the bottom cake with two more layers of cake.
Mermaid Cake Recipe & Tutorial
Print Pin Rate Share by Email Share on FB Save GrowDescription
Video
Ingredients
Cake batter
- 6 Eggs (large)
- 2 ½ cups (500 g) Sugar
- 1 cup (240 ml) Cooking Oil (flavorless)
- 5 cups (600 g) All-purpose flour
- 1 cup (240 ml) Buttermilk
- ½ cup (120 ml) Sour cream
- 3 tsp Baking powder
- 1 tsp Baking soda
- 1 tsp Salt
- 11/2 tbsp Vanilla extract
American Buttercream Frosting
- 1 lb (450 g) Unsalted butter (room temperature)
- 2 lbs (900 g) Powdered sugar (confectioners)
- 80 ml (⅓ cups) Heavy cream (dairy or non dairy )
- 2 tbsp Meringue powder
- 2 tsp Vanilla extract
Decorating
- 1 cup (240 ml) Simple syrup
- ½ lb (250 g) Fondant
- 1 tsp CMC
- 6 Food color gels (turquoise, purple, fuschia, pink)
- 1 Luster dust (White)
- 3 Petals dust (green, purple, blue)
Edible Sand
- ½ cup Cookie crumbs
- ¼ cup Brown sugar
- 1 tsp Luster dust (optional)
Instructions
Cake
- Preheat the oven at 165°C/325°F/ Gas Mark 3
- Grease and line with parchment paper 4 x 7-inch round cake pans (or 3 x 8-inch round cake pans).
- Dry ingredients – Combine flour, baking powder, baking soda, and salt – set aside.
- Eggs – In the bowl of a stand mixer with a whisk attachment on medium speed whip the whole eggs for 2 minutes. Gradually add the sugar a little at a time and continue to whip until the eggs are light and foamy or ribbon stagePro tip – adding the sugar gradually will prevent the eggs from separating.
- Oil – Next, gradually add the oil while whipping continuously. Pro tip – adding the oil gradually will help the oil emulsify with the eggs similar to mayonnaise.
- Combine – Next, add the flour mixture along with the buttermilk and sour cream in three or four batches. Scraping the sides of the bowl when necessary. Pro tip – Combine the buttermilk and sour cream together – use a whisk to ensure no lumps – set aside.
- Pans – Divide this batter between the four baking pans. I used cake strips to ensure I had flat cakes with no domes.Note – I divided the batter into 4 bowls and colored each in shades of pink (my daughter's request was pink inside) before I create a tie-dye kinda effect.
- Bake – Place the pans on the middle rack and bake for 30 to 35 minutes or until a skewer inserted in the center comes out clean. Pro tip – Rotate the pans between baking time (after 20 mins) top to bottom racks and vice versa.
- Cool – Once baked, cool on a wire rack for 10 minutes then invert cakes from the baking pans and cool completely. When cooled, wrap each cake in plastic wrap and let chill in the fridge for at least 4 hours.Pro tip – keeping the cakes in the pan for longer will make them soggy with the steam. Chilling cakes before frosting makes them easier to handle with fewer crumbs and breakage.
American Buttercream Frosting
- Meringue – In the bowl of a stand mixer with the paddle attachment, combine the meringue powder, heavy cream, and approximately two cups of powdered sugar. Whip starting on low speed until you have a thick, light, and sticky mixture. Pro tip – we make a meringue first this is what makes this buttercream different from other American buttercream recipes.
- Powdered Sugar – Next, gradually start adding the remaining powdered sugar in two batches. Pro tip – the mixture at the moment will be very dry and crumbly but continue to combine.
- Butter – Once all the butter is in – run the mixer on high for about 3 to 5 minutes more. Whip until you have a light and fluffy, creamy velvety texture very similar to whipped cream.Pro tip – do not skip on the whipping as this is what will give us that whipped cream-like consistency.
- Divide – Use 3 cups of buttercream for filling between the layers. The rest can be colored with gel food colorings – I used turquoise, purple, fuchsia, and pink. Place the colored buttercream in piping bags without tips.
Stacking the cake
- Syrup – Prepare simple syrup to moisten the cake layers. These will keep the cake moist for longer.
- Level, moisten – Using a bread knife or cake leveler cut the domes off the cake layers. Brush each layer with the cooled simple syrup. Pro tip -if you plan to move the cake again, it is best to use a cake circle under the cake, so you can pick the cake with its base and without any accidents.
- Two layers – Place a cake layer on the cake board or cake stand. Top with a big dollop of buttercream – spread evenly using a straight-edge spatula. Then top with the second layer.
- Dowel – Next, add 4 dowels in to the cake using the first as a guide to cut the others. Make sure they are straight at 90 degrees so they do not tilt. Then, place the 6-inch cake circle on top. Add a little more buttercream and spread with a spatula. Pro tip – doweling the cakes will prevent the bottom layers from sinking with the weight of the top layers.
- Next two layers – Then, top the three cake layer on top followed by more buttercream and the next layer. Pro tip – you need to dowel the cake only if you are using more than 3 layers of cake. 3 layers can be easily stacked without any support.
- Frost – Next, pipe the colored buttercreams all around the cake starting with the turquoise at the bottom, followed by the purple, fuchsia, and pink.Note – I wanted the top of the cake to look slightly narrow than the bottom. So, I use a 6-inch cake board as a guide to carve out the top crown. If you watch the video it will make sense.
- Smooth – Use a straight-edged spatula to spread the buttercream evenly as well as to marble some of the colors so they blend into each other.
- Pattern – Next, use the tip of a spatula to create lines all around the cake as shown in the video.
- Top – Finally, add more buttercream on top and smooth the top. Smooth it with an offset spatula.
- Chill – Place the cake in the fridge for at least 30 minutes before you assemble it. Pro tip -chilling will firm the buttercream which makes it easier to place all the edible decorating without a mess.
Mermaid tails, shells, seaweed, seashells
- Divide the fondant into smaller portions and use food gel colors to make different shades that will match the cake.Pro tip – Add ½ tsp of CMC to the fondant. This will ensure it holds its shape when molded.
- Tails – Create three mermaid tails free-hand as shown in the video or you can also use a mermaid tail silicone mold.
- Shells, corals – I used a seashell mold to make the seashells and corals. You can fill it with melted chocolate or use fondant as well.
- Seaweed – Cut strips of fondant in greens for the grass and seaweed.
- Dry – Place everything on a parchment-lined baking tray and let dry completely Pro tip – these will take 4 to 6 hours but can be made a few days in advance as well.
Assemble
- Decorations – Start by arranging the corals and grass around the cake. Then, add the seashells and the rest of the fondant accessories you created.Pro tip – these will stick easily on the buttercream so you don't need any water or edible glue.
- Center dowel – Finally, add three skewers on top of the cake and place the mermaid tails on it. Pro tip – these will hold the weight of the tails and prevent them from sinking into the cake as well as help support the cake with additional support.
- Sand – Add all the edible sand ingredients to a bowl and combine well. Spoon edible sand all around the cake and at the base of the mermaid tails.
- Ribbon – Don't forget to put a ribbon around the cake board. It completes the cake.
Recipe Notes & Tips
- Bake the cakes in advance so they have enough time to cool. Nothing is more frustrating than a melting frosting on a cake.
- There is no need to rush the process. Use the timeline given above to plan the cake. That way you will enjoy the process and do a good job too.
- I am using buttercream frosting that can stay out of the fridge for days but if you use perishable frosting make sure to keep it chilled in the cake.
- If you live in a hot and humid climate use a frosting that will give you enough time to frost, as well as travel to your final destination.
- A cold cake is easier to transport so always chill the cake well before you move it. Fewer accidents happen when the cake is well chilled.
- Don’t make haste. Stand back and look at the cake – see what looks good and where you can add more decorations. Since this is a buttercream cake place things correctly, so you don’t have to move them around.
- You may or may not need all the edible decorations you created, so don’t feel pressured to add it all. Sometimes less is more.
Conversions Used
1 lb = 453 grams, 1 cup = 240 ml, 1 stick = 113g, 1 tbsp= 15 ml, 1 tsp= 5 ml,
Nutrition Information
The nutrition information and metric conversion are calculated automatically. I cannot guarantee its accuracy. If this data is important to you please verify with your trusted nutrition calculator. Thank you
When I originally commented I clicked the “Notify me when new comments are added” checkbox and now each time a comment is added I get four emails
with the same comment. Is there any way you can remove people from
that service? Appreciate it!
Joie. Sorry about that. There should be an unsubscribe at the bottom of that email. Please click on that to unsubscribe from future comments. Sorry, the system works so you are in control, not me.