Make the coffee, put it in a wide bowl and to it add the amaretto, stir.
Put a pot of water on the stove, let it come to a boil and place a glass bowl on top, so that it sits above the water and doesn't actually touch it. Put the yolks, vanilla and sugar in the bowl and whisk for 10 min. until you get a creamy mixture. Remove from the stove, leave it to cool.
Beat the egg whites with a mixer with a pinch of salt, while gradually adding 2 tbsp sugar while beating, to get a stiff snow.
Transfer them to a different bowl and wash the bowl you used with the mixer. Dry it and pour the confectionery cream in it, turn the mixer on high and beat until creamy.
To the cooled yolk cream, add the mascarpone and stir carefully with a wooden spatula. Next, add the cream mixture, stirring again in one direction until fully absorbed.
In lots, add the egg whites as well, stirring carefully from the center of the bowl out toward the walls. You have to get an airy, fluffy cream.
Start to assemble the cake. Dip each biscotti in coffee and place a row of biscotti in a rectangular baking dish. Cover them with part of the cream on top, then place another layer of biscotti soaked in coffee and cream again. Continue in this order until you run out of ingredients. Be sure to finish off with cream.
Pass the cocoa (about 2 tbsp) through a fine sieve and sprinkle it along the entire surface of the cake. Put it in a fridge to cool and harden for a few hours.