Place the chocolate in top of a double broiler, bring water to a boil. reduce the heat to low; cook until chocolate melts. Gradually add 1 1/3 cups of boiling water, stirring constantly. Remove from heat; set aside.

Heat milk in a heavy saucepan just until thoroughly heated. DO NOT BOIL. Stir in the sugar and salt; add chocolate mixture, stirring well. Cook over low heat, stirring occasionally. Remove from heat; stir in vanilla. Top with marshmallows or whipped cream, if desired. serve immediately. Makes 6 cups