Step #1
Mix all the ingredients under cake to form a smooth batter, for 1-2 minutes Line a standard 12 hole muffin tray tin with muffin cases.
Step #2
Divide the mixture between the muffin cases.
Step #3
Bake in a preheated oven 180°C (360°F, Gas Mark 4) for 20-22 minutes until firm to the touch.
Step #4
Allow to cool completely before decorating. Place the stout into a saucepan, simmer over a low heat for 10-15 minutes until it has reduced to a thick syrup. Allow to cool.
Step #5
Sift the icing sugar into a bowl and add the butter, Beat until smooth and creamy for about 4-5 minutes with an electric whisk or machine, then add the reduced stout and mix well. Do not over beat or the mixture may become runny.
Step #6
Pipe the icing over the cupcakes and decorate with chocolate curls or cocoa powder.
