Fluffy White Icing(Frosting For  Chocolate Nugget Cake)  
["1 C sugar", "1/3 C water", "1/3 tsp. cream tartar", "2 egg whites", "1 1/2 tsp. vanilla", "2 blocks semi-sweet, unsweetened chocolate, melted"]
["Boil slowly sugar, water & cream of tartar, without stirring until syrup spins to 8 inch threads.", "Keep saucepan covered first 3 minutes to prevent crystals from forming on sides of pan.", "Remove from heat."]
["sugar", "water", "cream tartar", "egg whites", "vanilla", "semi-sweet"]