Soak the gelatin in water as directed on the package. Boil the milk and successively add the sugar and gelatin. Once the mixture has cooled down, add vanilla.
Put the dairy jelly in small bowls, preferably ones with an interesting shape, as for a cake and put it in a cold area to solidify. Serve by dipping each shape in hot water for a few seconds and turning it over out onto a saucer.
Put some caramel or chocolate topping on the plate in advance.