For the icing
- STEP 1
Heat the oven to 180C/160C fan/gas 4. Line a 12-hole bun tin with paper cases. Put the sugar and butter in a bowl and beat together until light and fluffy. Gradually mix in the eggs and vanilla until combined.
- STEP 2
Add the flour, cocoa powder and baking powder to the bowl and mix to make a smooth batter. Fold the milk through to loosen. Divide the mixture between the cases using a spoon. Bake for 20 mins, or until a cocktail stick poked into the centre of one of the cakes in the middle row comes out clean. Leave to cool in the tin for 5-10 mins, then transfer to a wire rack to cool completely
- STEP 3
While the cakes are cooling, make the icing. Beat together the butter, icing sugar and cocoa powder in a bowl for 5-10 mins, until you have a smooth, creamy consistency. Add the milk to loosen if needed. Pipe or spread on top of the cooled cupcakes.