This is an excellent all-purpose frosting that can be used to top any cake—from cupcakes to a multitiered wedding cake. Its flavor is adaptable, too; two of our favorite variations are lemon (which we paired with our Lemon Curd Cake, page 153) and chocolate (which adorns the Dobos Torte, page 203).

　　

Ingredients

makes 4 cups

　　4 large egg whites

　　1 1/4 cups sugar

　　3 sticks (1 1/2 cups) unsalted butter, room temperature, cut into tablespoons

　　1 teaspoon pure vanilla extract

　　

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 in vanilla. Beat on lowest speed to eliminate any air bubbles, about 2 minutes. Stir with a rubber spatula until frosting is smooth.

　　

Lemon Swiss Meringue Buttercream Variation

Step 4

Follow instructions for Swiss Meringue Buttercream, omitting the vanilla extract and stirring in 3/4 cup Lemon Curd (page 390) with a rubber spatula at the end.

　　

Chocolate Swiss Meringue Buttercream Variation

Step 5

Follow instructions for Swiss Meringue Buttercream, omitting the vanilla extract, decreasing the sugar to 1 cup, and adding 8 ounces melted best-quality bittersweet chocolate after the butter has been incorporated (let chocolate cool slightly before mixing in).

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