chocolate marshmallow sheet pan cake

Chocolate Marshmallow Cake

Because marshmallows are not just for campfires and candied yams.
Servings 20 people
Calories 258kcal


For the batter

  • 1 1/2 cups flour
  • 4 Tablespoons cocoa powder
  • 1/2 teaspoon fine sea salt
  • 1 cup (2 sticks) unsalted butter room temperature
  • 2 cups sugar
  • 4 eggs
  • 2 teaspoons vanilla extract

For the topping

  • 1 stick unsalted butter melted
  • 1/2 cup milk
  • 1 16 ounce box confectioner's sugar
  • 1/2 cup cocoa powder
  • 1 10 ounce bag mini marshmallows


For the cake

  • Preheat the oven to 350 degrees Fahrenheit. Prepare a lightly colored 9-inch by 13-inch cake pan by greasing the bottom of the pan.
  • Combine the flour, cocoa powder and salt in a large bowl and mix together.
  • Cream the room temperature butter and sugar together with a stand mixer, about 3-4 minutes on moderate speed or until light, fluffy and aerated.
  • Add the eggs to the creamed butter one at a time, beating lightly after each to incorporate them into the batter. Add the vanilla and mix briefly once more to combine all wet ingredients.
  • Slowly combine the dry ingredients with the wet ingredients in the stand mixer bowl, scraping the sides with a spatula as needed.
  • Pour the batter into the prepared cake pan, and bake for approximately 30 minutes or until batter is set and a toothpick inserted into the middle comes out clean.

For the topping

  • While the cake is baking, use a hand or stand mixer to combine the┬ámelted butter, milk, and cocoa. Add the confectioner's sugar 1/2 cup at a time until you've reached the desired consistency. Cover with plastic wrap until ready to use.
  • Immediately after the cake comes out of the oven, cover the top with marshmallows, then coat with the confectioner's frosting.


If using a ganache topping, place 1 cup of semi-sweet or dark chocolate chunks (or chocolate chips) in a medium bowl. Heat 1 cup of heavy cream in a small saucepan or in the microwave with a microwave-safe container until lightly simmering. Immediately pour the hot cream on top of the chocolate, and cover to contain the steam, about 5 minutes. Uncover and stir with a whisk until all the chocolate has melted and forms a smooth, shiny sauce.


Serving: 0g | Calories: 258kcal | Carbohydrates: 29g | Protein: 3g | Fat: 15g | Saturated Fat: 9g | Cholesterol: 69mg | Sodium: 76mg | Potassium: 80mg | Fiber: 1g | Sugar: 20g | Vitamin A: 480IU | Calcium: 21mg | Iron: 1mg