Description
This rich and tender Peanut Butter Sheet Cake delivers pure peanut butter bliss in every bite, topped with a thick, velvety peanut butter frosting. Baked in a 9×13″ pan and sized perfectly to serve a crowd, this easy, homemade cake is the perfect treat for potlucks, birthdays, or any time you crave a peanut butter dessert.
Ingredients
Scale
Cake
- 2 cups all-purpose flour
- 2 cups granulated sugar
- 3/4 tsp baking soda
- 1/2 tsp salt
- 1 cup water
- 3/4 cup unsalted butter
- 1/2 cup creamy peanut butter
- 1/2 cup buttermilk
- 2 large eggs
- 1 tsp vanilla extract
Frosting
- 1/2 cup unsalted butter
- 1/2 cup creamy peanut butter
- 1/4 cup milk (or buttermilk)
- 1 tsp vanilla extract
- 4 cups powdered sugar
Instructions
- Prepare the Oven and Pan: Preheat your oven to 350°F (175°C). Grease a 9×13-inch baking pan to prevent sticking and set aside.
- Combine Dry Ingredients: In a large mixing bowl, whisk together the flour, granulated sugar, baking soda, and salt until evenly blended.
- Make the Peanut Butter Mixture: In a saucepan over medium heat, combine water, unsalted butter, and creamy peanut butter. Stir constantly until the mixture is melted, smooth, and fully combined. Remove from heat.
- Mix Wet and Dry Ingredients: Pour the warm peanut butter mixture into your bowl with the dry ingredients. Stir until just combined.
- Add Remaining Wet Ingredients: In a separate small bowl, whisk together the buttermilk, eggs, and vanilla extract. Add this mixture to the batter and stir until smooth and well incorporated, but do not overmix.
- Bake the Cake: Pour the batter into the prepared pan. Bake for 25–30 minutes, or until a toothpick inserted in the center comes out clean or with just a few moist crumbs.
- Make the Frosting: While the cake bakes, melt unsalted butter and creamy peanut butter together in a saucepan over medium heat. Stir in the milk (or buttermilk) and bring just to a simmer, then remove from heat.
- Finish the Frosting: Whisk in the vanilla extract and gradually add the powdered sugar, whisking until the frosting is smooth, creamy, and free of lumps.
- Frost the Cake: Spread the frosting over the warm cake immediately after it comes out of the oven, smoothing it into an even layer.
- Cool and Serve: Allow the cake and frosting to cool completely in the pan before slicing and serving for optimal texture and flavor.
Notes
- The frosting sets as the cake cools, so spread it while both are still warm for the best results.
- For extra texture, try sprinkling chopped peanuts over the frosted cake.
- This cake stores well, covered, at room temperature for up to 3 days or refrigerated for up to 5 days.
- You can substitute whole milk for buttermilk if needed, though buttermilk adds tang and tenderness.
- Prep Time: 20 minutes
- Cook Time: 25 minutes
- Category: Desserts
- Method: Baking
- Cuisine: American
Nutrition
- Serving Size: 1 slice (1/16 of recipe)
- Calories: 350
- Sugar: 34g
- Sodium: 180mg
- Fat: 16g
- Saturated Fat: 7g
- Unsaturated Fat: 7g
- Trans Fat: 0g
- Carbohydrates: 48g
- Fiber: 1g
- Protein: 5g
- Cholesterol: 45mg