Ingredients

makes about 2 cups

　　2 large egg whites

　　1/2 cup packed light-brown sugar

　　1 1/2 sticks (3/4 cup) unsalted butter, cold, cut into tablespoons

　　

Step 1

In the heatproof bowl of an electric mixer set over a saucepan of simmering water, combine the egg whites and sugar. Cook, whisking constantly, until the sugar has dissolved and the mixture is warm to the touch (about 160°F).

　　

Step 2

Attach the bowl to the mixer fitted with the whisk attachment. Beat the egg-white mixture on high speed until it holds stiff (but not dry) peaks. Continue beating until the mixture is fluffy and cooled, about 6 minutes.

　　

Step 3

Switch to the paddle attachment. With the mixer on medium-low speed, add the butter several tablespoons at a time, beating well after each addition. (If the frosting appears to separate after all the butter has been added, beat on medium-high speed until smooth again, 3 to 5 minutes more.) Beat on lowest speed to eliminate any air bubbles, about 2 minutes. Stir with a rubber spatula until frosting is smooth.

　　Reprinted with permission from Martha Stewart's Baking Handbook by Martha Stewart. © 2005 Clarkson Potter