Preheat the oven to 180C/350F/Gas 4 and prepare two 12-hole tartlet tins with fairy cake cases.
Whisk together the eggs and sugar until light and fluffy.
Gradually add the flour and the butter, folding the mixture together gently.
Pour the mixture carefully into the fairy cake cases.
Bake the cakes for 10-15 minutes, until golden on top and a skewer carefully inserted into one of the cakes comes out clean. Allow to cool for ten minutes on a wire rack before removing from the tin.
To make the icing, whip together the icing sugar, butter and cocoa powder.
Once the cakes are cool, ice them liberally.
Decorate the cakes with chocolate buttons, sticking them on at a 90 degree angle in layers all the way around so each cake resembles a chrysanthemum flower.
