Separate the egg yolks from the whites. With a mixer, beat the egg yolks with powdered sugar, while gradually adding the cottage cheese, yoghurt and milk.
Gradually add the whites, whipped to snow, to the egg yolks, stirring with a whisk. Pour the ready to drink coffee into a large bowl with the liqueur. In a square or rectangular form, layer the bottom with a little cream.
Arrange half of the biscotti on top, which you've dipped briefly in the coffee with the rum. Put 1/2 of the cream on them. Arrange the remaining soaked in coffee biscotti.
Top with the rest of the cream, smooth it out and sprinkle it with the cocoa. Leave in the fridge for about 12 hours. Enjoy!