Bring the cream, milk and sugar together with the two tonka beans to a boil. Let the mixture simmer on a low heat for ten to fifteen minutes. Cool the mass and let the aroma steep. Take out the tonka beans, wash and dry them, this way you can use them several times.
Heat the cream mixture again to about 60 degrees, squeeze out the soaked gelatin sheets and dissolve in the liquid. Pour the cream into small dessert bowls and leave to set in the refrigerator for several hours.
In the adult version, after the gelatine has dissolved, the cream can be flavored with a dash of rum.