Food & Cooking Recipes Dessert & Treats Recipes Cake Recipes Vanilla Sheet Cake with Malted-Chocolate Frosting 3.1 (144) 5 Reviews By Martha Stewart Editors Martha Stewart Editors Facebook Instagram Twitter Website An article attributed to "Martha Stewart Editors" indicates when several writers and editors have contributed to an article over the years. These collaborations allow us to provide you with the most accurate, up-to-date, and comprehensive information available.The Martha Stewart team aims to teach and inspire readers daily with tested-until-perfected recipes, creative DIY projects, and elevated home and entertaining ideas. They are experts in their fields who research, create, and test the best ways to help readers design the life they want. The joy is in the doing. Editorial Guidelines Updated on October 18, 2019 Print Share Share Tweet Pin Email Servings: 12 Sheet cakes, long a staple of bake sales and potlucks, are easy to make and even easier to transport. Be sure to let the cake cool completely before you frost it. Once frosted, the cake can be covered with plastic wrap and kept at room temperature up to three days. Ingredients For the Cake ½ cup (1 stick) plus 1 tablespoon unsalted butter, room temperature, plus more for pan 2 ¼ cups all-purpose flour, plus more for pan 2 ¼ teaspoons baking powder ¾ teaspoon baking soda ½ teaspoon salt 1 cup plus 2 tablespoons sugar 3 large eggs 1 cup buttermilk 1 ⅛ teaspoons vanilla extract For the Frosting 3 tablespoons unsweetened cocoa powder 1 ¾ cups plus 2 tablespoons malted milk powder ¼ cup plus 2 tablespoons boiling water ¾ cup (1 ½ sticks) plus 1 ½ tablespoons unsalted butter, room temperature 10 ½ ounces milk chocolate, melted and cooled Pinch of salt Chopped malted milk balls (optional), for decorating Directions Make the cake: Preheat oven to 350 degrees. Lightly butter a 9-by-13-inch baking pan. Dust with flour, tapping out excess. In a large bowl, whisk together flour, baking powder, baking soda, and salt. With an electric mixer on high speed, beat butter and sugar until pale and fluffy, about 5 minutes. Beat in eggs, 1 at a time, until combined. Reduce mixer speed to low. Add flour mixture in 3 batches, alternating with 2 batches of buttermilk; beat to combine, scraping down sides of bowl as needed. Beat in vanilla. Transfer batter to prepared pan; smooth top with an offset spatula. Bake, rotating half way through, until cake is golden and puffed and a cake tester comes out clean, about 30 minutes. Transfer pan to a wire rack to cool completely. Meanwhile, make the frosting: In a medium bowl, whisk together cocoa and malted milk powders. Add the boiling water, whisk until smooth, and let cool. With mixer on high speed, beat butter until smooth. Add cocoa mixture; beat until combined. Add chocolate and salt. Raise mixer speed to medium- high; beat until frosting is smooth and peaks form, about 3 minutes. Spread frosting over cake; sprinkle with malted milk balls, if desired. Jonathan Lovekin Print