Step 1
Preheat oven to 160ºC / 180ºC fan/Gas Mark 3.
Step 2
Place butter and sugar into a bowl and beat until light, fluffy and pale in colour.
Step 3
Add eggs and flour and combine all the ingredients together.
Step 4
Separate the mixture evenly into three bowls and add purple, pink and blue food colouring to each.
Step 5
Using a tbsp or ice cream scoop, spoon each colour into the tin randomly and swirl with a toothpick for a marble effect. Bake for 25-30 minutes until well risen and firm to touch.
Step 6
Leave to cool in the tin for a few minutes then turn out onto a cooling rack. Leave to cool completly.
Step 7
Beat the the butter, sifted icing sugar and vanilla flavour together until smooth to make the buttercream..
Step 8
Trim and level your cakes. Layer each sponge using buttercream.
Step 9
Add the black food colouring to the remaining buttercream and coat the cake.
Step 10
Decorate with sprinkles and enjoy!
Tag @pmecake so we can see your amazing cakes!
Tip 1
To avoid a wonky cake, make sure your layers are neatly trimmed. For a straight top use a cake leveller and for the sides place a cake board slightly smaller than the cake and trim off the cake crust using a serrated knife!
Tip 2
Test bake your colours with a cupcake to help you decide on a shade of colour!