7-Minute Frosting 2 egg whites 1 cup granulated sugar 1/4 teaspoon cream of tartar 1/8 teaspoon salt 1/4 cup water 1 cup Marshmallow Crème 1 teaspoon vanilla extract Combine all ingredients except vanilla extract in the top of a double boiler. Place over boiling water. Beat until soft peaks form. Remove from heat and beat until stiff. Beat in vanilla extract.