This fabulous chocolate sheet cake only requires one pot for mixing and is topped with the most amazing milk chocolate ganache frosting.

Chocolate Sheet Cake with Milk Chocolate Ganache Frosting

This fabulous chocolate sheet cake only requires one pot for mixing and is topped with the most amazing milk chocolate ganache frosting.
Course Dessert
Cuisine American
Prep 20 minutes
Cook 35 minutes
Resting time 2 hours
Total 2 hours 55 minutes
Servings 12 to 16 servings
Calories 581 kcal
Author Michelle


For the Cake:

  • 1¼  cups all-purpose flour
  • 1½  cups granulated sugar
  • ½  teaspoon baking soda
  • ½  teaspoon salt
  • cup whole milk
  • ounces bittersweet chocolate  finely chopped
  • ¾  cup Dutch-processed cocoa powder
  • ⅔  cup vegetable oil
  • eggs
  • teaspoon vanilla extract

For the Frosting:

  • 16 ounces  milk chocolate finely chopped
  • ⅔  cup heavy cream
  • 16  tablespoons unsalted butter, cut into 16 pieces and softened
US Customary - Metric


  1. Make the Cake: Preheat oven to 325 degrees F. Lightly spray a 9x13-inch baking pan with non-stick cooking spray.
  2. In a medium bowl, whisk together the flour, sugar, baking soda, and salt; set aside.
  3. In a large saucepan, stir together the milk, chocolate, and cocoa powder. Place the saucepan over low heat and cook, whisking frequently, until the chocolate is melted and the mixture is smooth. Remove from the heat and cool for 5 minutes. Whisk the vegetable oil, eggs, and vanilla into the chocolate mixture until smooth and homogeneous (it may look curdled and separated at first, but keep whisking and it will come together!). Add the flour mixture and whisk until combined, making sure to scrape the corners of saucepan.
  4. Pour the batter into the prepared pan; bake until firm in center when lightly pressed and a toothpick inserted in the center comes out with a few moist crumbs attached, 30 to 35 minutes, rotating the pan halfway through baking. Cool the cake completely in the pan on a wire rack before frosting, 1 to 2 hours.
  5. Make the Frosting: While the cake is baking, combine the chocolate and cream in large heatproof bowl set over a saucepan filled with 1 inch of barely simmering water, making sure that water does not touch the bottom of the bowl. Whisk the mixture occasionally until the chocolate is uniformly smooth and glossy, 10 to 15 minutes. Remove the bowl from the saucepan. Add the butter, whisking once or twice to break up the pieces. Let the mixture stand for 5 minutes, then whisk until all of the melted butter is incorporated and the mixture is completely smooth. Refrigerate the frosting, without stirring, until cooled and thickened, 30 minutes to 1 hour.
  6. Once cool, whisk the frosting until smooth. (Whisked frosting will lighten in color slightly and should hold its shape on whisk.) Spread the frosting evenly over top of cake. Cut the cake into squares and serve out of pan. (Leftover cake can be refrigerated in airtight container for up to 2 days.)

Recipe Notes

Nutritional values are based on one serving

Nutrition Facts
Chocolate Sheet Cake with Milk Chocolate Ganache Frosting
Amount Per Serving
Calories 581 Calories from Fat 369
% Daily Value*
Fat 41g63%
Saturated Fat 26g163%
Cholesterol 86mg29%
Sodium 141mg6%
Potassium 280mg8%
Carbohydrates 54g18%
Fiber 4g17%
Sugar 39g43%
Protein 5g10%
Vitamin A 585IU12%
Vitamin C 0.1mg0%
Calcium 55mg6%
Iron 2.9mg16%
* Percent Daily Values are based on a 2000 calorie diet.