Put the milk and sugar in a pot on the stove to boil. Dissolve the gelatin in 2/5 cup (100 ml) of water, leave it for 10 minutes and then add the warm milk, while stirring. Allow the mixture to sit as is for 2-3 hours.
Whip 1 1/5 cups (300 ml) of the cream with a mixer and combine it with the milk. Divide the mixture into 3 parts. In the first, add 7 oz (200 g) of finely chopped chocolate wafers. In the second part, add 4/5 cup (200 g) ground walnuts and crumbled biscuits. The third part remains as is, without anything added.
Lay out the bottom of an oval oven dish with foil and pour the mixture with the wafers in. Pour the third part of the cream in and place the unfinished cake for 1 hour in the freezer.
Finally, add the part with the nuts and biscuits and leave it in the fridge to set. Take the cake out and cover it with 2/5 cup (100 ml) of whipped cream all over. Decorate the jellied cake with macaroons and biscuits of your choice.