Preheat the oven to 180°C/ 170°C fan/ Mk4. Half fill an oven proof container – a small cake tin is ideal – with water. Line the muffin tin with muffin papers, or grease and flour each hole individually.
In a small saucepan, melt together the butter and Billington’s sugars until the sugars are dissolved. Sift together the flour and baking powder.
Beat the eggs and Vanilla Extract. Allow the butter and sugar to cool slightly and stir in to the eggs. Immediately stir in the flour and baking powder.
Spoon into the muffin papers, about two-thirds full. Bake for 20 -25 minutes.
To make the icing, mix together the cocoa, espresso powder and hot water until dissolved for the mocha flavouring. Beat together the butter, Billington’s icing sugar and mocha flavouring, until well blended. Fill the piping bag, and pipe onto the muffins decoratively. Sprinkle with chocolate sprinkles and serve with hot coffee.