St Patrick's Day cupcakes

Preheat the oven to 180 C/350 F/Gas Mark 4. Line a 12 cup muffin tin with paper cases. Place the butter, stout and cocoa powder in a saucepan and place over a gentle heat, stir until the butter has melted and the mixture is smooth. Remove from the heat and allow to cool.

In a large bowl sift together the flour, salt, baking powder and sugar. Add the cooled stout mixture and beat for 1 minute using an electric whisk on a medium speed. Add the egg and sour cream and beat for a further 2 minutes.

Divide the batter evenly between the prepared tin. Bake for 20-25 minutes until cooked through and springy to the touch. Transfer the cakes to a cooling rack and leave to cool completely.

For the frosting, cream the butter in a bowl until light and fluffy. Gradually beat in the icing sugar a little at a time then beat in the Irish cream liquor. Spoon or pipe the icing on the cooled cakes and sprinkle with green sugar to decorate.