Heat the oven to 180ºc/Gas 4. Arrange 25 small cake cases on a baking tray or in a mini 24 cake hole tin.
Put the sugar and margarine in a bowl and mix.
Sift in the flour, cocoa powder into the bowl. Add the egg and stir all the ingredients together until creamy. Add the chocolate drops and stir in.
Using a teaspoon, spoon the mixture into the cases. Bake in the oven for 12mins. When ready, take them out of the oven to cool.
In the meantime make the icing. Sift the icing sugar into a bowl, add the warm water, peppermint essence and green food dye.
Stir the icing until its smooth. Use a teaspoon to spread a little icing onto each cake. Decorate the cakes the buttons and drops, you could even use chocolate shavings.
