Recipe from Martha Stewart
Yield 6 cups of frosting
1 1/4 cups sugar
1 1/2 tablespoons light corn syrup
5 large egg whites, room temperature
1) Bring 1 cup plus 2 tablespoons sugar, the corn syrup, and 3 tablespoons water to a boil, stirring. Wash down side of pan with a wet pastry brush, and cook sugar syrup, without stirring, until a candy thermometer registers 230 degrees.
2) Meanwhile, beat egg whites with a mixer until soft peaks form. Gradually beat in remaining 2 tablespoons sugar.
3)Add sugar syrup in a slow, steady stream down side of bowl. Beat on high speed until thick, fluffy, and cool, about 7 minutes.