Pre-heat your oven to 140C Fan/325F/Gas Mark 3, and line a cupcake tin with cupcake cases
For the cupcake sponge, mix together the butter and caster sugar, ideally using an electric mixer, for 5 minutes until smooth and fluffy
Add the eggs, peppermint extract and milk and whisk them in well
Then gently whisk in the self raising flour, baking powder and cocoa powder
Divide the mixture between the cupcakes cases, and bake them for 25-30 minutes or until a thin skewer inserted in the centre of the cupcakes comes out clean. Put them on a rack to cool completely
Make the green mint buttercream by mixing together the softened butter, peppermint extract, milk and icing sugar until smooth. You can do this by hand, but an electric whisk or stand mixer with paddle attachment will provide the best results. If the buttercream is too stiff, you can add a little more milk
Then add a small amount of green food colouring and mix until a pastel green shade is reached. You can add more food colouring if needed
Make the chocolate buttercream by mixing together the softened butter, cocoa powder, milk and icing sugar, and mix until smooth. You can do this by hand, but an electric whisk or stand mixer with paddle attachment will provide the best results. If the buttercream is too stiff, you can add a little more milk
Fill a piping bag fitted with your chosen nozzle, with the gren mint buttercream on one side and the chocolate buttercream on the other side
Spread or pipe the buttercream on top of the cupcakes
Decorate with the Aero Bubbles and chunks of Aero Bar
Store in an airtight container in a cool place and eat within 3 days