1. Pour 2 cups (500 ml) milk in a small pot. Set aside 8 tbsp of it to dissolve the pudding. Then add the sugar and pudding to the set aside milk and let the milk in the pot come to a boil.
2. Start pouring the mixture with the pudding slowly into the milk, in a thin trickle, stirring nonstop. Then remove from the stove and leave it to cool, stirring occasionally so a crust doesn't form.
3. Arrange a layer of biscuits along the bottom of a rectangular oven dish, while dipping each one in a bowl of milk. You're going to get a different number of layers depending on the size of the oven dish. Put pudding after each layer of biscuits. After the final layer, put a more generous amount of pudding and lay on jam for decoration.
Then, leave the cake in the fridge for 10-12 hours.