Choco-citrus Cakes

For the cupcakes: preheat the oven to 200�C (180� fan) 400�F gas 6. Grease a 12 hole muffin tin.

Sift the flour, cocoa and bicarbonate of soda into a mixing bowl. Stir in the sugar.

Whisk the buttermilk with the eggs and pour into the dry ingredients. Add the melted butter and fold in gently until just combined. The mixture will be lumpy.

Spoon the mixture into the tins to cover the bases and make a slight hollow in the centre. Spoon in about 1 heaped teaspoon of lemon curd and cover completely with more mixture.

Bake for 20-25 minutes until risen and springy to the touch. Cool in the tins for a few minutes, then place on a wire rack to cool completely.

For the topping: heat the cream in a pan and bring to a boil. Immediately remove from the heat and pour over the chocolate. Stir until the chocolate has melted, then stir in the vanilla.

Add the butter gradually and stir until blended. Allow to cool until the mixture is thick enough to pipe.