Peanut Butter Sheet Cake
This Peanut Butter Sheet Cake is a moist, soft, and tender cake packed with peanut butter flavor. Topped with a creamy and smooth chocolate peanut butter frosting and colorful mini M&M's. It's quick to make and perfect for all occasions!
Servings: 16 servings
Ingredients
Peanut Butter Cake
- 1/4 cup creamy peanut butter
- 1 cup water
- 1/2 cup salted butter
- 1 cup granulated sugar
- 1 cup brown sugar
- 2 cups all-purpose flour
- 1 teaspoon baking soda
- 2 whole large eggs at room temperature
- 1/2 cup buttermilk
- 1 1/2 teaspoons vanilla extract
- 3/4 cup mini M&ms
Chocolate Peanut Butter Frosting
- 1 cup salted butter softened at room temperature
- 1/4 cup creamy peanut butter
- 3-4 cups powdered sugar sifted
- 1/2 cup cocoa powder
- 1 teaspoon vanilla extract
- 3-5 tablespoons heavy whipping cream or milk
Instructions
To make the cake
- Preheat the oven to 375 degrees F. Grease or line a half sheet pan with parchment paper (12x17 jelly roll pan).
- In a medium pot on medium heat, add the peanut butter, water, and butter. Bring to a boil then remove from heat.
- In a large mixing bowl, mix sugars, flour, and baking soda with a whisk.
- Add the peanut butter mixture and stir until barely combined.
- Add the eggs, buttermilk, and vanilla and stir until combined. Be sure not to over-mix.
- Pour the cake batter into the prepared sheet pan and bake for 13-15 minutes or just until the center is set. Be sure not to over bake! Let cool and make frosting.
To make the frosting
- In a large bowl, cream together the butter until fluffy and no lumps remain. Add peanut butter and mix to combine.
- Turn the mixer on low and beat in 2 cups of powdered sugar until combined.
- Add in the cocoa powder and vanilla extract. Mix again.
- Add the remaining powdered sugar and 1 tablespoon of milk at a time until consistency is reached. If the frosting is too thick, add more milk, if it's too thin, add more powdered sugar.
- Top cooled cake with frosting and sprinkle on mini M&Ms. Cut into squares and enjoy!