Separate the egg whites from the yolks. Beat the whites to a thick snow with 2 tbsp powdered sugar.
Caramelize the sugar with 2-3 tbsp water and then add it to the whites, pouring it in a thin trickle, while constantly stirring with a mixer.
Beat the yolks with the rest of the powdered sugar and chopped into pieces butter. Add the vanilla and stir.
Combine the 2 creams, while stirring with a spoon nonstop.
Then arrange biscotti once again and cover with cream. Repeat in this order until out of ingredients. You have to finish with a layer of cream.
Decorate the cake with orange rinds, sprinkle with walnuts and hazelnuts and put it in the fridge until it's time to serve.