Squeeze the lemon, collect the juice and, if necessary, use the zest to zest.
Mix lemon juice, ricotta, mascarpone, limoncello, sugar and salt into a smooth cream. If the cream is too firm, add a little more limoncello or milk to taste. Add the sugar to taste.
Put a good dash of milk with a little limoncello in a deep plate. I make two parts milk and one part liqueur. Briefly turn the biscuits in this liquid and, if necessary, roughly crumble them in glasses or lay out the bottom of an appropriate shape whole. Spread the cream on top. Decorate with the zest and leave to steep in the refrigerator overnight.