Food & Cooking Recipes Dessert & Treats Recipes Cake Recipes Chocolate Sprinkle Sheet Cake Be the first to rate & review! 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 28, 2021 Print Rate It Share Share Tweet Pin Email Prep Time: 35 mins Total Time: 2 hrs 10 mins Yield: 10 to 12 Serves A light chocolate cake is not a contradiction in terms; it's a splendid anytime snack. Here, some of the flour in our basic recipe is replaced with a half-cup of cocoa powder for a deep chocolate flavor. Sour cream creates a tender crumb, and buttercream frosting gets whipped until airy with an electric mixer. Last but by no means least: Sprinkles make everything joyous. Ingredients Cake 1 stick unsalted butter, melted and cooled, plus more, softened, for pan 1 ⅓ cups unbleached all-purpose flour ½ cup Dutch-process cocoa powder, sifted 2 teaspoons baking powder 1 teaspoon kosher salt (we use Diamond Crystal) 4 large eggs, room temperature 1 ½ cups granulated sugar 2 teaspoons pure vanilla paste or extract 1 cup sour cream, room temperature Frosting 2 sticks unsalted butter, softened 2 cups confectioners' sugar, sifted ½ cup Dutch-process cocoa powder, sifted ¼ cup whole milk, room temperature 2 tablespoons chocolate sprinkles, for decorating Directions Cake: Preheat oven to 350°F. Brush a 9-by-13-inch or 8-by-12-inch baking pan with butter. Line with parchment, leaving a 2-inch overhang on long sides. Butter parchment. Whisk together flour, cocoa, baking powder, and salt. Combine eggs and granulated sugar in the bowl of a mixer fitted with the whisk attachment. Beat on high speed until thick and pale, about 4 minutes. Add flour mixture; beat just to combine. Add butter and vanilla; beat to combine. Add sour cream; beat until smooth. Scrape batter into prepared pan, smoothing top with a spatula. Bake until top springs back when lightly touched and a tester inserted in center comes out clean, 30 to 35 minutes (for 9-by-13-inch) or about 40 minutes (for 8-by-12). Let cool in pan on a wire rack 10 minutes. Using parchment overhangs, lift out of pan and let cool completely on rack. (Cake can be made to this point and stored at room temperature, wrapped in plastic, up to 1 day.) Frosting: Beat together butter, confectioners' sugar, cocoa, and milk on medium-high speed until light and fluffy, about 5 minutes. Spread over top of cake. Decorate with sprinkles. Frosted cake is best the day it's assembled, but can be refrigerated, wrapped in plastic, up to 1 day. Return to room temperature before serving. Con Poulos Rate it Print