Food & Cooking Recipes Dessert & Treats Recipes Cake Recipes Velvet Cocoa Cake with Instant Buttercream 3.7 (145) 4 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 April 15, 2020 Print Rate It Share Share Tweet Pin Email Prep Time: 35 mins Total Time: 1 hrs 15 mins Servings: 12 Indulge in a slice of rich chocolate cake made with buttermilk, butter, and plenty of cocoa powder. It's topped with a super easy buttercream recipe that uses marshmallow cream for the base, plus two kinds of chocolate—cocoa powder and semisweet chocolate chips. Ingredients For the Cake 12 tablespoons (1 ½ sticks) unsalted butter, room temperature, plus more for pans 2 ½ cups all-purpose flour, plus more for pans ¾ cup cocoa powder 1 teaspoon baking soda ¼ teaspoon salt 1 cup granulated sugar 1 cup light-brown sugar 3 large eggs 2 teaspoons vanilla extract 1 ½ cups buttermilk For the Buttercream 1 cup (2 sticks) unsalted butter, room temperature 2 jars (7.5 ounces each) marshmallow cream ⅔ cup cocoa powder ⅔ cup semisweet chocolate chips, melted and cooled 1 tablespoon vanilla extract Directions Make the cake: Preheat oven to 350 degrees. Butter and lightly flour two 9-inch round cake pans. In a bowl, whisk flour, cocoa, baking soda, and salt. In a mixing bowl, cream butter and sugars until fluffy. Add eggs, one at a time, beating until well incorporated. Beat in vanilla. Add the flour mixture to the butter mixture in three additions, alternating with buttermilk and beginning and ending with the flour mixture. Scrape bowl as needed. Pour batter into pans. Bake until toothpick inserted in center comes out clean, 25 to 30 minutes. Cool in pans 10 minutes before inverting cakes onto rack to cool completely. Make the buttercream: In mixing bowl, beat butter and marshmallow cream until fluffy. Beat in cocoa, chocolate, vanilla, and 1 tablespoon water. If too thin, refrigerate about 5 minutes. Place one layer on platter. Spread top with 1 cup buttercream. Place second layer on top. Frost entire cake with remaining buttercream. Cook's Notes To melt chocolate, heat in the microwave for 15-second intervals until almost melted, then stir to finish melting. The cake can be frosted in advance and refrigerated. Rate it Print