Created by Sugarkins on December 16, 2012
Step 1: Bring 2 cups water to a simmer in a medium saucepot.
Step 2: In a large glass bowl that will fit over the saucepan, combine 1/4 cup water, sugar, salt, corn syrup, cream of tartar, and egg whites. Place on top of the saucepan and beat for 7 minutes using an electric hand mixer. The frosting will be smooth, shiny, and form peaks when the mixer is lifted from the bowl.
Step 3: Remove from the heat and slowly beat in the marshmallow cream.
Step 4: Spread over cooled cake.