Preheat oven at 180°C/ 350°F/ Gas Mark 4
Base:
125g butter
125g caster sugar
125g self raising flour
2 medium eggs
2 drops vanilla essence
1 tbsp cocoa powder
Icing:
150g unsalted butter
225g icing sugar
2tbsp warm milk
2 drops vanilla essence
Mix the ingredients together and split the mixture (except the cocoa powder) in two and add the cocoa powder in one of the halves. Fill in the cupcake holders with the chocolate mix for the base and top up with the vanilla mix.