Light and fluffy marshmallow frosting is a snap to make. Best of all, unlike regular frosting, it's not fully vegetable shortening. Many frostings contain trans-fat as well. Marshmallow frosting lacks that overkill of richness and sweetness that most frostings have.
Combine the sugar, egg whites, cream of tartar, corn syrup and water in the top of a double boiler.
Place over boiling water and beat until stiffs peaks form.
Scrape the bottoms and sides of the pan.
Remove the double boiler from heat and add in the marshmallows.
Beat with an electric mixture until the frosting is thick enough to spread.
Use the marshmallow frosting immediately to frost cakes and confections.