Preheat the oven to 190°C/ 170°C fan/ gas mark 5/ 375°F
Line the bun tins with 20 paper cases
For the cakes:
Beat the cake ingredients together thoroughly using any method: wooden spoon, hand or stand mixer, or processor(Butter, caster sugar, eggs, flour, baking powder, salt, vanilla extract)
Put a heaped teaspoon of mixture into each paper case
Cook for 15-20 minutes until the cake surface springs back when you touch it lightly with your fingertip
Leave in the tin for 5 minutes, then remove and leave to cool on a wire rack.
For the buttercream:
Beat the softened butter and vanilla extract with an electric whisk
Add the icing sugar gradually, beating well as you go
To decorate the cakes:
Use a small, sharp knife to cut a cone-shaped out of the cake. Start near one edge and push the point down and towards the centre. Keeping the point in the same place, move the knife round the cake.