Decorating square cakes while similar to round cake is not necessarily the same. A few tips and trick as discussed in this post go a long way. My Simple, easy and effortless method of getting sharp edges on square cakes can be used whether you use buttercream or ganache to frost the cake.
The basic process is the same
- It doesn't matter what cake recipe you bake, or whether it's a tiered or single cake. The process is the same.
- Level the cake, trim any uneven edges and ensure the cake is straight on all sides. Trimming the sides and edges are necessary, so you will not have a bulge. Seen my Tip Thursday on bulges on cakes for more details.
- Torte your cake, fill and crumb coat the cake as usual - watch video sharp edges on cakes for cake decorating basics.
- Buttercream two opposite sides of the cake leaving excess around all edges (a large overhang / lip).
Buttercream opposite two sides first
- Chill for at least ah hours or until the buttercream is firm enough to cut. This is very important, so do not rush this process.
Tip - Do not freeze the cake. Freezing will give you tiny ice crystals on the buttercream that can melt under fondant and cause issues.
- Once firm, use a sharp knife to cut the excess buttercream edges maintaining a nice straight line. Use a ruler to help if needed.
Buttercream remaining two sides
- Now, buttercream the remaining two sides again leaving an excess at the edges.
- Chill again at least an hour. Once chilled, cut the excess Buttercream with a sharp knife.
Frost the top
- Since the cake is well chilled smoothing the top and sides is done effortlessly using a bench scraper.
- Continue with fondant or decoration as needed.
Tips when decorating square cakes
- Square cakes use more batter than round cakes which also means that square cakes have more servings. For example, an 8-inch square cake has more servings than an 8" square cake - see Cake Serving Chart Guide; Popular Tier Combinations cake serving chart here.
- Needless to say - square cakes need more batter than round cakes. For example, an 8" round cake and 7" square cake use the same amount.
- Always use the right size baking pan and combinations. For example - while a 10, 8, 6 works great for a stacked tiered cake, it does not necessarily work for square cakes - See popular tier combinations here
- When frosting square cakes - ensure you have the same amount of buttercream on all sides of the cake. Or you may find that your cake is a wee bit bigger on one side. In single tier cakes it doesn't matter much but in a tiered cake, it shows.
- When frosting - keep the square sharp at all times. Working to add frosting equally on all sides.
- Use hot water and a metal scraper to smooth the sides.
- If necessary chill the cake between the smoothing process.
- When covering square cakes with fondant? You can use both drape method as well as panel method.
Unless necessary I prefer panel method as it gives you instant sharp straight edges, unlike the drape method where you have to make spend time creating.