Rich Chocolate Icing(This Chocolate Icing Is Easy To Make.)  
["1/2 c. sugar", "1 sq. (1 oz.) chocolate, shaved", "1/2 c. boiling water", "1 tsp. vanilla", "1 1/2 Tbsp. cornstarch", "1/4 tsp. salt", "1 1/2 Tbsp. butter"]
["Combine, in a double boiler, the sugar, salt, cornstarch and chocolate.", "Add boiling water and cook until thick.", "Remove from heat, stir in butter and vanilla and beat well.", "Let cool, then spread on cake."]
["sugar", "chocolate", "boiling water", "vanilla", "cornstarch", "salt", "butter"]