• Preheat the oven to 160 C / 320 F.
• Prepare two 8 inches round pans for baking - grease and line them.

Wet ingredients 

• In one mixing bowl combine the yogurt, milk, eggs, oil, and vanilla.
• Use a whisk to make sure the eggs are well incorporated.
• Then add the coffee and combine well - set aside

Dry ingredients

• Use a bowl large enough for the final batter.
• Combine flour, sugar, cocoa powder, baking soda, baking soda, and salt.
• Use a whisk to combine well

Combine wet to dry 

• Make a hollow in the center of the dry ingredients and pour in the wet ingredients.
• Use a whisk to combine the two slowly so you have a smooth, no lumpy batter.
• Lastly, add the boiling water. Use a whisk to ensure no lumps
• Divide the batter into your prepared baking pans.
• Bake in a preheated oven for 25 to 30 mins.

Prepare Frosting

• In the stand mixer with the paddle attachment (or hand mixer) cream butter until light and fluffy.
• Add salt, whipping cream and vanilla - mix a minute, until well combined
• Now add the powdered sugar one cup at a time.
• Once all the powdered sugar has been incorporated
• Continue to mix on medium-high for 2 to 3 minutes more until you have a light and fluffy buttercream.
• The cream in the mixture will whip and give you almost stiff peaks.
• Tip: If you do not whip enough the buttercream will be soft consistency which may not be pipeable. So whip until you have a stable whipped cream kinda light and fluffy frosting.

Assemble

• Prepare simple syrup – cool completely before using.
• Once cooled, cut the domes off the cake layers.
• Brush each layer with the cooled, simple syrup.
• Place a cake layer on the cake board or cake stand.
• Top with a big dollop of buttercream – spread evenly.
• Then top the second cake layer on top followed by more buttercream and next layer until you have used up all four layers.
• Place the cake in the fridge for 15 minutes, so the layers hold together.
• Spread the remaining buttercream around and top of the cake. (I colored the remaining buttercream pink, purple, blue, red,)
• Use a bench scraper to smooth the sides of the cake and an offset spatula to smooth the top
• If desired place the remaining frosting in a piping bag and pipe swirls or borders on the cake.