Sieve the flour, cocoa powder and baking powder into a bowl, then mix in the margarine and caster sugar. Add the eggs into the mixture one at a time, beating well after each addition. Whisk until light and fluffy. Divide mixture into cupcake cases.
Bake for 15 to 17 minutes until a skewer inserted into the centre comes out clean. Allow to cool before icing.
Make the buttercream, divide into 3 bowls and add colour paste to each bowl. Mix till the colour is even. Spoon onto the cupcake and using a knife spread to the edges.
Using a serrated knife carefully score a chocolate biscuit in half. Using some melted chocolate, dip the end of the biscuit into the chocolate and place onto a chocolate button, with a cocktail stick in between. Repeat for the second ‘wing’ and leave to set. Add another button for the face to sandwich in the biscuit corners. Add two eyes from the Cake Angels Trick or Treat Pumpkin 2Ds.
Allow to fully set before placing flying bat on top of cupcake.