Separate the eggs into yolks and whites, placing them in separate bowls. It is important that no yolk gets into the whites, as it will prevent them from whipping to stiff peaks.

Whisk the egg whites to stiff peaks using an electric mixer. 

Next, whisk the egg yolks and sugar together with the electric mixer until you obtain a fluffy and almost white mixture. 

Stir in the mascarpone into the egg yolk mixture using a spoon, then gently fold in the stiffly beaten egg whites to get a light and airy cream. Fill the cream into a piping bag. 

In a bowl, mix cold coffee and the chosen spirit. Cover the bottom of 6 glasses with the mascarpone cream. Dust with a little sifted cocoa powder. 

Break each ladyfinger in half and dip them one at a time into the coffee mixture. Distribute a thin layer of ladyfingers over the mascarpone cream in the glasses. Add another layer of cream, and continue layering in this order until the glasses are filled. 

Cover the glasses with plastic wrap and place them in the refrigerator for at least 6 hours. 

When serving, garnish with a little sifted cocoa powder.