Place water in small bowl, prinkle the gelatin over the cold water and set aside to soften. Combine the chocolate, confectioners' sugar and milk in a heavy saucepan. Set over moderate heat; cook, stirring occasionally with a wire whisk, until the chocolate has melted and the mixture comes just to a boil, thickens slightly, and is smooth. Remove from the heat and add the softened gelatin, granulated sugar and salt. Stir with the whisk until all have dissolved; blend in the vanilla and set aside.
Whip the cream until it holds a semifirm shape, not until stiff. Refrigerate. Place the bowl of chocolate mixture in a larger bowl partly filled with ice and cold water. Stir frequently with the whisk until the mixture thickens to the consistency of a medium cream sauce and feels cool to the touch. Watch carefully toward the end, for it will thicken quickly.
When the chocolate mixture is ready, fold in the chilled whipped cream with the whisk. When it is blended, pour into a glass bowl (6 cup capacity). Cover with plastic wrap and refrigerate until set (several hours or overnight). When ready to serve, garnish the top with chocolate shavings. (*Shavings are quickly made by holding a block of semisweet chocolate in your hand to warm it slightly; shave as many strips as desired with a vegetable peeler.) 8 servings.