In a mixing bowl, beat the eggs and sugar together until pale and creamy.
Blend in the mascarpone.
In a separate dish, mix together the brandy, rum and coffee, and dip each sponge finger or boudoir biscuit into this before layering them on the bottom and around the sides of a shallow serving dish.
In a separate bowl, whisk the egg whites until stiff.
Using a metal spoon, fold the whites into the mascarpone mixture until well blended.
Spoon this over the fingers or biscuits and smooth the surface.
Sprinkle the top with grated chocolate, cover with cling film and refrigerate for at least 6 hours or, ideally, overnight as this will allow the dish to set completely, and the flavours to blend together properly.