This chocolate version of old-fashioned cornstarch-thickened blancmange is what the pudding in the box is supposed to taste like. If you don't want to use cream, just increase the milk to 2 cups.
In a heavy saucepan, scald the milk. In a small bowl, mix the cornstarch, sugar, salt and cream. Stir this mixture into the scalded milk and cook over low heat until it thickens. Cook, stirring, a few minutes more.
When the mixture is silky, take it off the heat and add the vanilla and chocolate bits or cocoa. Stir until chocolate is melted. Pour into serving dishes and chill. Makes 4 servings.