Dessert & Treats Recipes Cake Recipes Fillings & Frostings Buttercream Frosting Recipes Brown Sugar Swiss Meringue Buttercream 3.4 (78) 8 Reviews By Martha Stewart Test Kitchen Martha Stewart Test Kitchen The recipes developed by our test kitchen team have undergone a rigorous process of development and testing, ensuring that every element is optimal, from ingredient amounts to method and cooking time. This process includes triple-testing recipes to ensure they meet our high standards. The many stellar cooks and food editors who have been part of our team include Sarah Carey, Lucinda Scala Quinn, Jennifer Aaronson, Shira Bocar, Anna Kovel, Greg Lofts, Riley Wofford, Lauren Tyrell, and Lindsay Leopold. Editorial Guidelines Updated on May 16, 2017 Print Rate It Share Share Tweet Pin Email Photo: Maura McEvoy Yield: 5 cups This intensely rich, silken frosting works well on spice, carrot, or pound cakes. Try it on our Caramelized-Apple Spice Cake. Ingredients 5 large egg whites 1 ⅔ cups packed dark-brown sugar ¼ teaspoon salt 4 sticks (2 cups) unsalted butter, room temperature Directions Put egg whites, sugar, and salt into a heatproof bowl set over a pan of simmering water. Whisk until mixture registers 160 degrees, about 4 minutes. Beat on high speed until stiff, glossy peaks form, about 6 minutes. Reduce speed to medium-low. Add butter, 2 tablespoons at a time, beating after each addition (meringue will deflate slightly as butter is added). Beat until frosting is smooth and glossy, 3 to 5 minutes. Cook's Notes Buttercream can be refrigerated airtight for up to 3 days; bring to room temperature, and beat before using. Rate it Print