Mini M&M Chocolate Sheet Cake
This Mini M&M Chocolate Sheet Cake is made with an incredibly moist homemade chocolate cake, topped with a rich, creamy fudge frosting, and finished with a generous layer of colorful Mini M&M's. It's an easy, crowd-pleasing dessert that's perfect for birthdays, holidays, potlucks, bake sales, or anytime you're craving a classic chocolate cake with a fun twist.
Servings: 12 slices
Ingredients
For the cake:
- ½ cup salted butter melted. you can use unsalted if you prefer!
- ¼ cup vegetable oil
- 2 cups granulated sugar
- 1 tsp vanilla extract
- ¾ cup unsweetened cocoa powder I prefer Hershey's Special Dark but you can use natural cocoa powder as well!
- 2 eggs room temperature
- 2 cups all-purpose flour
- 2 tsp baking powder
- 1 ½ tsp baking soda
- ½ tsp kosher salt
- 1 cup buttermilk room temperature
- 1 cup hot coffee or hot water
For the frosting:
- 1 cup salted butter room temperature. you can use unsalted if you prefer!
- 6 ounces semi-sweet baking chocolate melted, slightly cooled
- ¾ cup unsweetened cocoa powder I prefer Hershey's Special Dark but you can use natural cocoa powder as well!
- 4 cups powdered sugar
- 2-4 tbsp heavy cream room temperature
- 1 tsp vanilla extract
- ¼ tsp kosher salt
- 3-4 cups mini M&Ms For the look pictured, I used almost 2 (9.4-ounce) sharing-size bags of Mini M&M's to completely cover the top of the cake. You can absolutely use less if you'd like more of the fudge frosting to show through!
Instructions
For the cake:
- Preheat the oven to 350°F. Grease a 9x13-inch baking pan. In a large bowl, whisk together the flour, sugar, cocoa powder, baking powder, baking soda, and salt.
- Add the eggs, melted butter, vegetable oil, buttermilk, and vanilla. Mix until just combined. Slowly pour in the hot coffee, mixing until the batter is smooth. The batter will be thin.
- Pour the batter into the prepared pan and bake 28-32 minutes, or until completely baked through. Allow to cool completely before frosting.
For the frosting:
- In the bowl of a stand mixer beat the butter until smooth and creamy, about 2-3 minutes. Mix in the melted chocolate and then the cocoa powder until fully combined.
- Add half of the powdered sugar, then mix in 2 tablespoons of heavy cream, vanilla, and salt. Add the remaining powdered sugar and beat for 1-2 minutes until smooth, fudge & spreadable. Add 2-3 more tablespoons of heavy cream if needed to reach desired consistency.
- Spread the frosting evenly over the cooled cake and immediately sprinkle the Mini M&M's evenly over the frosting, gently pressing them into place. Slice into squares and enjoy!