Finely crumble the biscuits to a flour-like texture then add the melted butter. Mix well and place the mixture on the bottom of the cake tin, taking care to press well.
Preparation of the cream
Beat the egg yolks with sugar and then add the ricotta.
When this mixture is blended add the melted chocolate and the cold coffee.
Add the stiff egg-whites and the chocolate shavings.
Pour the cream over the cooled crust and put in refrigerator.
Just before serving, add the chopped hazelnuts.