Dessert & Treats Recipes Cake Recipes Fillings & Frostings Buttercream Frosting Recipes Chocolate Buttercream for Haunted-House Cake 3 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 March 23, 2020 Print Rate It Share Share Tweet Pin Email Photo: Johnny Miller Yield: 12 cups Use this decadent frosting to decorate our creepy Haunted-House Cake. Egg whites keep it light and fluffy and melted semisweet chocolate make every bite taste rich and decadent. Ingredients 10 large egg whites 2 ½ cups sugar 2 pounds (8 sticks) unsalted butter, cut into tablespoons, room temperature 24 ounces semisweet chocolate, melted and cooled Directions Combine egg whites and sugar in the heatproof bowl of a standing mixer; set over a saucepan of simmering water, whisking (by hand) until sugar dissolves and mixture registers 160 degrees on a candy thermometer, about 5 minutes. Transfer bowl to mixer, and whisk on high speed until stiff, glossy peaks form and mixture is cool, about 10 minutes. 3. Reduce speed to medium, and add butter, 1 tablespoon at a time, whisking until combined before adding more. Reduce speed to low; whisk in chocolate, then whisk over medium-high until well combined. Buttercream can be refrigerated up to 3 days, or frozen up to 1 month, in an airtight container. Before using, bring to room temperature and beat on low speed until smooth. Rate it Print