From the Kitchen of: Martha Stewart
1 ½ cups sugar
2 tbsp light corn syrup
6 large egg whites
1 tsp pure vanilla extract
In the heatproof bowl of an electric mixer set over a saucepan of simmering water, combine sugar, corn syrup, 1/4 cup water, and egg whites. Cook over medium heat, stirring frequently, until mixture registers 160° on an instant-read thermometer, about 2 minutes. Attach bowl to a mixer fitted with the whisk attachment. Beat mixture on high speed until glossy and voluminous, about 5 minutes. Beat in vanilla. Use immediately.
Best with White Layer Cake with Lemon Curd Filling.