Pre-heat your oven to 160C Fan/350F/Gas Mark 4 and line a cupcake tin with paper cases
To make the cupcakes, mix together the butter and caster sugar until smooth and fluffy, ideally with an electric mixer
Add the eggs and Baileys, and mix well
Add the self raising flour, cocoa powder and baking powder and whisk or fold in gently
Divide the mixture between the cupcakes cases, and bake them for 20-25 minutes or until a thin skewer inserted in the centre of the cupcakes comes out clean. Put them on a rack to cool completely
To make the buttercream, mix the butter on it's own for 2-3 minutes, then add the icing sugar and the Baileys and mix until smooth. For best results use an electric hand whisk or a stand mixer with the paddle attachment
Pipe the buttercream onto each cupcake using a piping bag fitted with a nozzle. Or spread on with a spoon
Decorate with the truffles, paper straws and gold edible glitter
Store in an airtight container in a cool place, eat leftovers within 3 days