1. Put 1 cup sugar, the corn syrup, and 1/2 cup water into a small heavy saucepan over medium heat. Cook, stirring occasionally, until mixture just begins to simmer and sugar has dissolved, about 6 minutes. Wash down sides with a wet pastry brush to prevent crystals from forming. Raise heat to medium-high. Cook, without stirring, until a candy thermometer reaches 235 degrees.

2. Meanwhile, put egg whites into the bowl of an electric mixer fitted with the whisk attachment. Beat on medium speed until soft peaks form. Gradually add remaining tablespoon sugar, and beat until peaks are fluffy but still soft. Slowly pour in hot sugar syrup down side of bowl. Raise speed to high, and beat until mixture has cooled and stiff peaks form, about 7 minutes. Use immediately.