Chocolate Marshmallow Frosting

Chocolate Marshmallow Frosting
(amount for 1 cake or 1 tray of brownies)

2 egg whites
1 cup sugar
6 packets Sweet 'N Low® granulated sugar substitute
½ teaspoon cream of tartar
1 tablespoon light corn syrup
1/3 cup water
3/4 cup marshmallow cream or 16 marshmallows
4 tablespoons cocoa

Combine egg whites, sugar, Sweet 'N Low, cream of tartar, syrup, and water in top of double boiler. Place over boiling water; beat with a rotary beater until stiff peaks form, scraping pan occasionally. Remove from heat. Add sifted cocoa and marshmallow cream and continue beating until it is of spreading consistency. Spread over cooled brownies.