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Homemade Peanut Butter Sheet Cake photo

Peanut Butter Sheet Cake

This Peanut Butter Sheet Cake is a crowd-pleaser! Moist, tender, and topped with creamy frosting, it’s perfect for any occasion.
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Prep Time 15 minutes
Cook Time 30 minutes
Total Time 45 minutes
Servings: 12 servings
Course: Dessert
Cuisine: American
Ingredients Equipment Method Notes

Ingredients
  

For the Cake:
  • 1/4 cup creamy peanut butter
  • 1 cup water
  • 1/2 cup butter
  • 1 cup sugar
  • 1 cup brown sugar
  • 2 cups flour
  • 1 teaspoon salt
  • 1 teaspoon baking soda
  • 1/2 cup buttermilk (see note for easy substitution)
  • 1 teaspoon vanilla extract
For the Frosting:
  • 3/4 cup butter softened
  • 6 tablespoons buttermilk
  • 1/2 cup peanut butter
  • 3 1/2 cups powdered sugar
  • 1 tablespoon vanilla extract

Equipment

  • Mixing bowls
  • Whisk
  • Measuring cups and spoons
  • Baking Sheet
  • Spatula
  • Cooling rack

Method
 

Instructions
  1. Step 1: Preheat your oven to 350°F (175°C). This ensures your cake bakes evenly and rises properly.
  2. Step 2: Grease and flour your baking sheet to prevent the cake from sticking. You can also line it with parchment paper for easy removal.
  3. Step 3: In a large mixing bowl, whisk together the peanut butter, water, butter, sugar, and brown sugar until smooth. This mixture should be creamy and well-combined.
  4. Step 4: In another bowl, whisk together the flour, salt, and baking soda. Gradually add the dry ingredients to the wet mixture, mixing until just combined.
  5. Step 5: Beat the eggs in a separate bowl, then add them to the batter along with the buttermilk and vanilla extract. Stir until fully incorporated. The batter will be slightly runny, which is perfect for a moist cake!
  6. Step 6: Pour the batter into the prepared baking sheet and spread it out evenly. Bake for 25-30 minutes, or until a toothpick inserted into the center comes out clean.
  7. Step 7: Once baked, remove the cake from the oven and allow it to cool in the pan for about 10 minutes. Then transfer it to a cooling rack to cool completely.
  8. Step 8: While the cake cools, prepare the frosting. In a mixing bowl, beat together the softened butter, buttermilk, peanut butter, powdered sugar, and vanilla extract until smooth and fluffy.
  9. Step 9: Once the cake is completely cooled, spread the peanut butter frosting evenly over the top using a spatula. Be generous with the frosting because it’s the best part!
  10. Step 10: Cut the cake into squares and serve. This Peanut Butter Sheet Cake is perfect for any occasion, and it pairs wonderfully with a glass of cold milk or a cup of coffee.

Notes

  • Ensure all ingredients are at room temperature for better blending.
  • Don’t overmix the batter; stop mixing as soon as the flour is incorporated to keep the cake light and fluffy.
  • Store leftovers in an airtight container at room temperature for up to 3 days.