Marshmallow Frosting

1 1/3 cups granulated sugar
1/2 cup water
6 large marshmallows
3 egg whites
1/8 teaspoon salt
1 teaspoon vanilla extract

Boil sugar and water without stirring until syrup spins a thread; melt marshmallows in syrup; pour slowly over stiffly beaten egg whites, beating constantly. Add flavoring and spread very thickly.