Around 6 servings
Make espresso and cool it down, then add cognac to taste.
Lay out lady fingers at the bottom of a dish (20 square-cm / square).
Pour the coffee/cognac mix with a spoon over the ladyfingers.
Separate the eggs. Beat the egg yolks with sugar, then add mascarpone. Mix well. Beat the egg whites. Fold them into mascarpone mix with a spatula.
Spread the mixture over the lady fingers.
Dust with cocoa powder.