The Ultimate Chocolate Peanut Butter Sheet Cake (From Scratch)

Some flavor combos never get old, and chocolate with peanut butter is at the top of that list. It’s rich, it’s nostalgic, and it hits every time.

This chocolate peanut butter sheet cake brings those two together in the most satisfying way possible. Think deep chocolate flavor, a tender and moist crumb, and a thick layer of creamy peanut butter frosting that makes every bite feel like comfort food at its best. Whether you’re baking for a birthday, a potluck, or just a regular Tuesday, this recipe is a guaranteed win.

Craving more one‑pan crowd‑pleasers? Head over to our Ultimate Guide to Sheet & Snack Cakes for the full collection and all the pro tips in one place.

Why This is the Perfect Sheet Cake Recipe

Before you grab your mixing bowls, here’s why this recipe works—and why it’s the one you’ll come back to over and over again.

Unbelievably Moist
This cake stays soft for days. That’s thanks to a mix of buttermilk and oil, which keeps the texture tender without turning dense or greasy.

Rich, Deep Flavor
It’s not just chocolate, it’s chocolate with depth. Hot coffee (you won’t taste it) brings out the cocoa’s natural bitterness and gives the cake a fuller, more intense flavor.

Foolproof Peanut Butter Frosting
Smooth, creamy, and just the right amount of sweet. Using processed peanut butter (like Jif or Skippy) gives you the perfect consistency—no oil separation, no gritty texture.

Made for Sharing
No fussy layers or complicated techniques. Just one 9×13 pan, one batch of frosting, and enough to serve a crowd. It’s easy, dependable, and always disappears fast.

The Science of Our Ingredients

This isn’t just a good recipe, it’s one that makes sense. Every ingredient has a job to do. Here’s why they matter and how they work together to give you the best possible results.

For the Moist Chocolate Sheet Cake

All-Purpose Flour
The base of the cake. It provides structure without making the crumb too heavy.

Granulated Sugar
Adds sweetness and helps lock in moisture. It also contributes to the cake’s tender texture.

Dutch-Process Cocoa Powder
This gives a smoother, darker chocolate flavor than natural cocoa. It reacts differently with leavening agents, so we balance it with both baking soda and baking powder.

Baking Soda & Baking Powder
These two work together to give the cake just the right lift. Baking soda reacts with the buttermilk’s acidity, while baking powder adds extra rise for a fluffier texture.

Salt
It sharpens the chocolate flavor and keeps the sweetness in check.

Eggs
They bind everything together and add richness. Room temperature eggs mix more evenly into the batter.

Buttermilk
The acidity in buttermilk tenderizes the flour’s gluten, giving you a softer crumb. It also adds a subtle tang that balances the sweetness.

Vegetable Oil
Keeps the cake incredibly moist—more so than butter—and helps it stay that way even in the fridge.

Vanilla Extract
Rounds out the chocolate flavor and adds depth.

Hot Coffee
This is the secret weapon. It dissolves the cocoa powder and brings out its full flavor. The cake won’t taste like coffee—it’ll just taste more chocolatey.

For the Creamy Peanut Butter Frosting

Unsalted Butter
Softened butter gives the frosting a light, spreadable texture. Starting with unsalted lets you control the overall flavor better.

Cream Cheese
Balances the sweetness with a touch of tang and makes the frosting extra smooth.

Creamy Peanut Butter
Stick to processed brands. Natural peanut butter can separate and leave the frosting oily. Jif or Skippy are perfect here.

Powdered Sugar
Sifted for a silky texture, it sweetens the frosting and helps it hold its shape.

Vanilla Extract
Adds warmth and depth.

Salt
A pinch keeps the frosting from being too sweet.

Heavy Cream or Milk
Just a little helps adjust the consistency if needed, making the frosting easier to spread.

How to Make Chocolate Peanut Butter Sheet Cake: Step-by-Step

This cake comes together in a few easy stages. You don’t need any special tools, just a couple of bowls, a whisk, and a pan. Here’s how to do it right, from batter to frosting.

Step 1: Combine the Dry Ingredients

In a large mixing bowl, whisk together the flour, sugar, cocoa powder, baking soda, baking powder, and salt. Sifting helps remove lumps, but a thorough whisking works too. This step ensures even distribution of the leavening agents.

Step 2: Whisk the Wet Ingredients

In a separate bowl, combine the eggs, buttermilk, oil, and vanilla extract. Whisk until the mixture is smooth and fully blended. This helps the batter come together quickly without overmixing.

Step 3: Combine and Bake

Pour the wet ingredients into the dry ingredients. Stir gently with a spatula or whisk just until you stop seeing dry flour. Now slowly add the hot coffee, mixing carefully until the batter is fully combined. It will look thin, don’t worry, that’s what gives the cake its moisture.

Pour the batter into a greased or parchment-lined 9×13 pan. Bake at 350°F for 33 to 37 minutes. A toothpick inserted in the center should come out with a few moist crumbs.

Let the cake cool completely in the pan on a wire rack before frosting.

Step 4: Make the Peanut Butter Frosting

Using a stand mixer or hand mixer, beat the softened butter and cream cheese together on medium-high speed for 2 to 3 minutes until smooth.

Add the peanut butter and mix again until fully combined and fluffy.

Turn the mixer to low and slowly add the sifted powdered sugar, vanilla extract, and salt. Mix until incorporated, then beat on medium-high for another 2 to 3 minutes. If the frosting feels too thick, add a tablespoon or two of cream or milk to loosen it up.

Step 5: Frost and Garnish the Cooled Cake

Spread the frosting evenly over the completely cooled cake with an offset spatula. Top with chopped Reese’s cups or peanuts for an extra layer of texture and flavor.

Pro Tips for a Perfect Cake Every Time

Even simple recipes can go sideways without a few good habits. These tips will help you avoid the common slip-ups and get the best results every time.

• Measure Your Flour the Right Way
  Don’t scoop directly from the bag. Instead, spoon the flour into your measuring cup and level it off with a knife. Too much flour makes the cake dense and dry.
• Don’t Overmix
  Once the wet and dry ingredients are combined, stop stirring as soon as the batter comes together. Overmixing develops gluten, which can make the cake tough.
• Use Room Temperature Ingredients
  Cold eggs and buttermilk don’t blend as well, which can lead to uneven texture. Let them sit out for about 30 minutes before you start.
• Cool the Cake Completely Before Frosting
  Frosting a warm cake is a fast track to a melted mess. Wait until the cake is fully cooled so the frosting stays smooth and neat.
• Thin Batter Is Normal
  The hot coffee makes the batter very runny—that’s expected. It bakes into a super moist, tender cake.

Variations and Topping Ideas

Want to switch things up or add your own flair? These ideas let you make the recipe your own without sacrificing the flavor or texture that makes it so good.

Frosting Swaps

• Chocolate Ganache
  For a richer finish, pour a warm layer of chocolate ganache over the cooled cake before or after adding peanut butter frosting.
• Chocolate Cream Cheese Frosting
  If you love tangy and sweet together, this variation gives you a slightly denser frosting with a deeper chocolate bite.

Topping Ideas

• Chopped Reese’s Peanut Butter Cups
  Press them into the top of the frosting for a visual wow factor and extra flavor.
• Salted Peanuts
  Crushed or whole, they add crunch and a salty contrast to the sweet frosting.
• Chocolate Sprinkles
  A fun option for birthdays or kids’ parties.
• Flaky Sea Salt
  Just a pinch on top sharpens the chocolate flavor and balances the sweetness.
• Melted Peanut Butter Drizzle
  Warm a little peanut butter and drizzle it over the frosted cake for an easy upgrade.

In a Hurry? The Cake Mix Shortcut

Short on time? You can still get all the flavor with half the effort. Start with a box of yellow cake mix and let the frosting do the heavy lifting.

Mix one box of yellow cake mix with 1⅓ cups water, ⅓ cup peanut butter, ⅓ cup vegetable oil, 3 eggs, and 1 teaspoon vanilla extract. Beat for 2 minutes, bake at 350°F in a greased 9×13 pan for 20–25 minutes, and frost with our homemade peanut butter frosting once cooled.

Storing and Freezing Instructions

This cake keeps well, which makes it great for making ahead or enjoying over a few days. Here’s how to store it without losing texture or flavor.

Storing at Room Temperature

If your kitchen is cool, you can cover the cake tightly and leave it at room temperature for up to 2 days. Use a cake container or press plastic wrap against the cut edges to keep it from drying out.

Storing in the Refrigerator

To extend freshness, cover the cake tightly and refrigerate it. It will keep well for 4 to 5 days. The texture stays soft thanks to the oil-based batter, and the frosting holds up nicely in the cold.

Before serving, let slices sit at room temperature for 15–20 minutes to take the chill off and bring back the full flavor.

How to Freeze

You can freeze the cake whole or in slices.

• Whole Cake: Chill the cake first to firm up the frosting. Then wrap it tightly in plastic wrap followed by a layer of foil. Freeze for up to 3 months.
• Individual Slices: Wrap each slice in plastic wrap and place them in a freezer-safe container. Great for quick snacks or single servings.

To thaw, place in the fridge overnight or let sit at room temperature for a few hours. The texture and flavor will come back perfectly.

Chocolate Peanut Butter Sheet Cake Recipe (Printable Card)

The BEST Chocolate Peanut Butter Sheet Cake (Easy & Moist)

Yield: 12 to 16 servings

Prep Time: 20 minutes

Cook Time: 35 minutes

Cooling & Frosting: 45 minutes

Total Time: 1 hour 40 minutes

A rich, moist chocolate sheet cake topped with the creamiest peanut butter frosting. This easy dessert is made in a 9x13 pan, perfect for birthdays, potlucks, or any day that needs something sweet. Includes from-scratch and cake mix shortcut versions.

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Ingredients

For the Chocolate Cake (From Scratch)

• 1 ¾ cups (210g) all-purpose flour
• 2 cups (400g) granulated sugar
• ¾ cup (63g) Dutch-process cocoa powder, sifted
• 2 tsp baking soda
• 1 tsp baking powder
• 1 tsp salt
• 2 large eggs, room temperature
• 1 cup buttermilk, room temperature
• ½ cup vegetable oil
• 2 tsp vanilla extract
• 1 cup hot coffee (or hot water)

For the Peanut Butter Frosting

• 1 cup (2 sticks) unsalted butter, softened
• 8 oz full-fat block cream cheese, softened
• 1 cup (270g) creamy peanut butter (Jif or Skippy)
• 3 cups (336g) powdered sugar, sifted
• 2 tsp vanilla extract
• ¼ tsp salt
• 2 tbsp heavy cream or milk (as needed)
• Optional: Chopped Reese’s cups or salted peanuts

Instructions

1. Preheat Oven: Set to 350°F (180°C). Grease or line a 9x13 pan with parchment.
2. Mix Dry Ingredients: Whisk together flour, sugar, cocoa, baking soda, baking powder, and salt.
3. Mix Wet Ingredients: In another bowl, whisk eggs, buttermilk, oil, and vanilla.
4. Combine: Pour wet into dry, mix just until combined.
5. Add Coffee: Slowly stir in hot coffee. Batter will be thin.
6. Bake: Pour into pan and bake 33–37 minutes. Cool completely on a wire rack.
7. Make Frosting: Beat butter and cream cheese until smooth. Add peanut butter, then powdered sugar, vanilla, and salt. Beat until fluffy. Add cream if needed.
8. Frost Cake: Spread frosting over cooled cake. Garnish with toppings if desired.

Notes

• You can substitute the frosting with chocolate ganache or chocolate cream cheese frosting.
• For a shortcut version using cake mix, scroll to the “Variations” section in the article.

Nutrition Information:

Yield: 16 Serving Size: 1 slice
Amount Per Serving: Calories: 520Total Fat: 28gSaturated Fat: 11gCholesterol: 65mgSodium: 290mgCarbohydrates: 65gSugar: 48gProtein: 6g

Nutrition information is automatically calculated and may vary based on specific ingredients and brands used. For the most accurate results, please calculate using your preferred nutrition tool.

Frequently Asked Questions (and Troubleshooting)

Even with a straightforward recipe, questions pop up. Here’s a quick guide to fix common problems and adjust the recipe to suit different needs.

Final Thoughts

This chocolate peanut butter sheet cake hits every mark—it’s easy to make, incredibly moist, and full of rich, nostalgic flavor. Whether you’re baking from scratch or taking the shortcut with a box mix, the result is a dessert that feels both classic and indulgent.

It’s the kind of recipe you keep in your back pocket for birthdays, holidays, or just when you want to treat yourself and others to something memorable. The frosting alone is enough to make it a crowd favorite.

Save it, share it, and come back to it—because once you’ve made it, you’ll understand why this one stands out.

Love This Recipe? Discover More Sheet & Snack Cake Favorites

If this Chocolate Peanut Butter Sheet Cake hit the spot, don’t miss The Ultimate Guide to Sheet & Snack Cakes. Inside you’ll find crowd‑pleasing classics, creative twists, and foolproof frosting tips—from Strawberry Cheesecake Dump Cake to Lemon Blueberry. There’s a one‑pan wonder for every occasion, and this guide will help you pick the next one.