Step 1

Melt the chocolate in a bowl set over a pan of simmering water. (Do not allow the base of the bowl to touch the surface of the water.) Allow to cool until the chocolate no longer feels hot to the touch.

Step 2

Beat the butter in a bowl until soft, then gradually beat in the icing sugar. Add the vanilla extract and beat again.

Step 3

Fold in the melted chocolate until completely incorporated (add a few drops of milk if the mixture is a little stiff).

Step 4

This icing can be kept in the fridge for a few days. Bring to room temperature and beat again until smooth before icing your cake.