Preheat the oven to 200°C/Fan 180°C/gas 6.
Place fairy cake cases into a 12-hole bun tin
Beat sugar and butter in bowl and gradually add eggs and vanilla essence.
Add the flour, cocoa and baking powder and mix to a smooth batter. Fold through the milk to loosen.
Alternatively – mix all ingredients together at once until a smooth batter!
Fill each paper case with the mixture.
Bake for 15–20 minutes or until the cakes are well risen and spring to the touch. Lift the paper cases out of the bun tin and cool the cakes on a wire rack.
To make the icing, beat the butter and icing sugar together until well blended. (option to add melted chocolate for a dark filling.
Cut a slice from the top of each cake and cut this slice in half. Place a teaspoon of raspberry or cherry jam in the centre then pipe a swirl of butter cream onto the top.
Place the half slice ‘wings’ on top to resemble butterfly wings.
Dust the cakes with icing sugar to finish.