To make strong coffee for this recipe, dissolve
4 tbsp of instant coffee in 4 tbsp of boiling water.
Heat the oven, line the tins and make the sponge as described in the 'goes well with' recipe, sifting the cocoa powder with the flour and baking powder.
For the filling, beat the mascarpone and sugar together, then beat in the coffee. Use half the mix to sandwich the cakes and spread the other half over the top, swirling with the back of a spoon to make pointy curls. Finely grate the chocolate over the top, then serve.