Preheat the oven to 180 degrees celcius/350F/Gas 4. Line 2 x 20cm (8in) cake tins with baking paper. Place the flour, cocoa, baking powder, butter, sugar, eggs and milk in a bowl and beat with an electric mixer for 2 minutes, or until completely mixed.

Spoon into tins, and spread out level. Bake for 25 minutes, until risen and springy. Cool for 5 minutes, in tins, then turn out onto a wire baking rack to cool completely.

Fill the cakes with Jam and Cream. Sprinkle remaining Caster Sugar on top of cake.