Separate eggs. Beat egg yolks with half of sugar over a hot water bath (preferably with an electric mixer). Remove from the heat, stir until cold and gradually mix in mascarpone. Beat egg whites with remaining sugar until stiff and fold into mascarpone mixture. Beat cream until stiff and fold into mascarpone mixture.
Mix coffee with brandy. Briefly soak half of ladyfingers and line the bottom of a flat 18 x 25 cm baking dish (approximately 7 x 10 inches) with it. Spread half of cream mixture on it and smooth. Top with a second layer of soaked ladyfingers and spread remaining cream on it.
Chill at least 3 hours. Dust with cocoa powder before serving.