How to make
Beat the milk with the powdered sugar and butter for 10-15 minutes. Add the eggs and egg yolk one by one, while continuously beating. Crumble the biscuits and add them to the mixture along with the walnuts, cocoa, vanilla, grated lemon rind and rum.
Stir the mixture well, pour it into oiled baking paper, shape it into a roll and wrap it tightly in the paper. Put the roll in the fridge to harden.
Loosen the tight roll, then roll it in powdered sugar. Serve it cut into slices.
