Caramel Seven-Minute Frosting
["2 unbeaten egg whites", "1 1/2 c. dark brown sugar", "1/4 tsp. cream of tartar", "1/3 c. cold water", "dash of salt", "1/2 tsp. maple flavoring"]
["Place all ingredients, except maple flavoring, in top of double boiler (not over heat); beat 1 minute with electric beater to blend.", "Place over boiling water on low to medium heat and cook, beating constantly, about 7 minutes.", "Do not overcook. Remove from boiling water.", "Add maple flavoring and beat 2 more minutes."]
["egg whites", "brown sugar", "cream of tartar", "cold water", "salt", "maple flavoring"]