Dessert & Treats Recipes Cake Recipes Fillings & Frostings Buttercream Frosting Recipes Brown Sugar Buttercream 3.7 (116) 7 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 Prep Time: 25 mins Total Time: 25 mins Yield: 4 cups Use this brown sugar buttercream on our Triple-Layer Apple Cake. If the mixture seems to have separated after all the butter is incorporated, beat on medium-high until smooth. Reduce speed to low; beat 3 minutes more. Ingredients 4 large egg whites 1 cup packed light-brown sugar ¼ teaspoon salt 1 ½ cups (3 sticks) unsalted butter, room temperature, cut into tablespoons Directions In a heatproof bowl set over (not in) a pan of simmering water, whisk together egg whites, sugar, and salt. Cook, whisking constantly, until the sugar has dissolved and the mixture is warm to the touch. Transfer to the clean bowl of an electric mixer. Beat on medium speed until fluffy and cooled, about 15 minutes. Raise speed to high; beat until stiff peaks form. Reduce speed to medium-low; add butter, 2 to 3 tablespoons at a time, until fully incorporated. Rate it Print