Grate the chocolate and put it in a double boiler with the water and sugar; let the water in the surrounding boiler boil fifteen minutes, beat well, and add the milk. Stir until thoroughly mixed, and the milk is very hot. Take from the fire, add the vanilla, and when the mixture is cold, freeze, turning slowly all the while. Serve in chocolate cups with the whipped cream on top.
This will fill nine chocolate cups.