Beat the mascarpone, cream, milk and vanilla in a suitable bowl.
Dip the biscotti in the cup of coffee for a few seconds, to soak them on all sides. Arrange the biscotti in a plate or cup.
Pour on half of the mixture. Arrange another layer of biscotti and pour on the rest of the mixture.
Grate the chocolate on top (you can use chocolate sprinkles).
Put in the fridge for several hours before serving.