When it comes to comfort food desserts, few things satisfy like a moist, sweet, nutty Peanut Butter Sheet Cake. This southern-inspired dessert combines the rich flavor of creamy peanut butter with a buttery, soft cake base and a smooth, glossy peanut butter frosting poured on while the cake is still warm. The result? A melt-in-your-mouth indulgence that’s perfect for potlucks, family gatherings, holidays, or anytime your sweet tooth strikes.
Whether you’re already a peanut butter enthusiast or simply love sheet cakes for their convenience and crowd-pleasing nature, this recipe checks every box. In this article, we’ll walk through the ingredients, preparation, expert tips, and FAQs to ensure your sheet cake is a huge success.
Why You’ll Love This Peanut Butter Sheet Cake
- One Bowl Simplicity: Minimal dishes and quick cleanup.
- Rich, Nutty Flavor: Peanut butter adds depth and creaminess to every bite.
- Feeds a Crowd: The jellyroll pan yields plenty of servings.
- Pour-Over Frosting: The warm frosting seeps into the cake for a gooey finish.
- Perfect for Any Occasion: Great for birthdays, barbecues, and casual Sunday dinners.
Ingredients You’ll Need
For the Cake:
- 1/4 cup creamy peanut butter – Adds rich, nutty flavor.
- 1 cup water – Helps bring ingredients to a boil for moist texture.
- 1/2 cup butter – For that classic buttery base.
- 1 cup granulated sugar – Sweetness and structure.
- 1 cup brown sugar – Moisture and a hint of molasses flavor.
- 2 cups all-purpose flour – The foundation of the cake.
- 1 teaspoon salt – Balances the sweetness.
- 1 teaspoon baking soda – Helps the cake rise.
- 2 eggs – Bind and enrich the batter.
- 1/2 cup buttermilk – Adds tang and tenderness.
- 1 teaspoon vanilla extract – Enhances flavor.
For the Frosting:
- 3/4 cup butter – Creates a velvety frosting.
- 6 tablespoons buttermilk – Keeps the frosting creamy.
- 1/2 cup peanut butter – Main flavor for the frosting.
- 3 1/2 cups powdered sugar – Sweetness and smooth texture.
- 1 tablespoon vanilla extract – Completes the flavor.
Step-by-Step Directions
1. Preheat and Prep
Preheat your oven to 375°F (190°C). Grease or line a 12×17 inch jellyroll pan (cookie sheet with raised edges) with parchment paper to prevent sticking.
2. Cook the Peanut Butter Mixture
In a medium saucepan, combine:
- 1/4 cup peanut butter
- 1 cup water
- 1/2 cup butter
Bring the mixture to a gentle boil, stirring occasionally. Remove from heat once fully combined and smooth.
3. Combine Dry Ingredients
In a large mixing bowl, whisk together:
- 1 cup sugar
- 1 cup brown sugar
- 2 cups flour
- 1 teaspoon salt
- 1 teaspoon baking soda
Use a fork or whisk to break up any clumps.
4. Assemble the Batter
Pour the dry ingredients into the warm peanut butter mixture and stir until just combined.
Add in:
- 2 eggs
- 1/2 cup buttermilk
- 1 teaspoon vanilla
Mix until smooth, but do not overmix.
5. Bake the Cake
Pour the batter into the prepared jellyroll pan and spread evenly.
Bake for 15 minutes, or until a toothpick inserted into the center comes out clean and the cake is lightly golden.
6. Make the Frosting
While the cake is baking, make the frosting:
In a small pot, combine:
- 3/4 cup butter
- 6 tablespoons buttermilk
- 1/2 cup peanut butter
Bring to a boil, then immediately remove from heat. Add:
- 3 1/2 cups powdered sugar
- 1 tablespoon vanilla extract
Whisk until smooth and pourable.
7. Frost the Cake
As soon as the cake comes out of the oven, pour the warm frosting evenly over the top. Spread gently with a spatula to cover every corner. The frosting will seep slightly into the cake for an ultra-moist finish.
Let cool slightly before slicing.
Tips for Success
- Use creamy peanut butter (not natural) for the best texture.
- Buttermilk adds moisture and tenderness—if you don’t have any, mix 1/2 cup milk with 1/2 tablespoon vinegar or lemon juice and let it sit for 5 minutes.
- Pour the frosting while warm to allow it to melt into the cake.
- For a twist, sprinkle chopped peanuts or chocolate chips over the frosting while it’s still warm.
Frequently Asked Questions (FAQs)
Can I use natural peanut butter?
It’s best to use traditional creamy peanut butter like Jif or Skippy. Natural peanut butter can separate and affect the texture of the cake and frosting.
What’s the best way to store leftovers?
Store covered at room temperature for up to 3 days, or in the refrigerator for up to 5 days. Let slices come to room temperature before serving for best texture.
Can I make this in a different size pan?
Yes! A 9×13 inch pan works well for a thicker cake—just increase baking time to about 25 minutes.
Is this recipe freezer-friendly?
Absolutely! Wrap individual pieces in plastic wrap and freeze for up to 2 months. Thaw overnight or microwave gently before serving.
Can I make this cake nut-free?
To make it nut-free, try using SunButter (sunflower seed butter) instead of peanut butter. Keep in mind it may alter the flavor and color slightly.
Variations to Try
- Chocolate Peanut Butter Sheet Cake: Add 1/4 cup cocoa powder to the dry ingredients and top with chocolate chips.
- Peanut Butter Banana Sheet Cake: Add 1 mashed ripe banana to the wet ingredients for a subtle banana twist.
- PB&J Style: Swirl a few spoonfuls of your favorite jelly into the batter before baking for a nostalgic twist.
Final Thoughts
This Peanut Butter Sheet Cake is not just a dessert — it’s a warm, gooey slice of heaven. It combines the comforting flavors of peanut butter, buttery cake, and melt-in-your-mouth frosting in a way that’s simple yet unforgettable. The cake is soft and fluffy, the frosting decadent and slightly gooey, making every bite absolutely indulgent.
Whether you serve it warm with a scoop of vanilla ice cream, pack it into a lunchbox, or share it at a potluck, this dessert is guaranteed to become a favorite in your baking repertoire.
Ready to make it? Just grab your jellyroll pan and whisk — this is one sweet memory waiting to be made.
Happy baking!