Reeses Peanut Butter Sheet Cake
This Reeses Peanut Butter Sheet Cake swirls peanut butter frosting and chocolate syrup right into the batter for a rich, gooey slice every single time.
Reeses Peanut Butter Sheet Cake is a swirled sheet cake made by marbling peanut butter frosting and chocolate syrup into a peanut butter cake batter, then topping it with more frosting and chopped Reeses cups. This recipe makes a full 9×13 pan, comes out dense and fudgy with pockets of melted chocolate cup running through it, and is perfect for potlucks, birthdays, or any weeknight when you need something bigger than a bowl of ice cream can fix. Here’s everything you need to make it perfectly.
I burned the edges on my first attempt at this Reeses Peanut Butter Sheet Cake because I got impatient with the swirling step and left the oven door open too long checking on it. Don’t do that. The peanut butter and chocolate marbling only works if you commit to it fast, and once you see how it bakes up you’ll get why people request this at every gathering.
Table of Contents
Why You’ll Love This Reeses Peanut Butter Sheet Cake
The peanut butter cake base is dense and moist, not dry like a lot of sheet cakes end up, and the swirled frosting layer bakes into gooey pockets instead of just sitting on top. It comes together in one bowl for the batter and one for the frosting, so cleanup is minimal.
This is a crowd-pleasing dessert that holds up fine at room temperature for a few hours, which makes it genuinely good for potlucks and bake sales. And the chopped Reese’s cups on top mean nobody’s confused about what flavor they’re getting.
What Ingredients Do You Need for Reeses Peanut Butter Sheet Cake?
| Ingredient Group | Ingredient | Amount | Notes |
|---|---|---|---|
| Main Batter | Creamy peanut butter | 1 cup | Room temperature blends easier |
| Main Batter | Unsalted butter | 8 tablespoons | Softened |
| Main Batter | Granulated sugar | 1 cup | |
| Main Batter | Large eggs | 4 | Add one at a time |
| Main Batter | Pure vanilla extract | 1 teaspoon | |
| Main Batter | All-purpose flour | 1 cup | |
| Main Batter | Milk | 1/2 cup | |
| Optional Base | Chocolate cake mix | 1 box | For a chocolate cake version |
| Frosting & Topping | Powdered sugar | Amount not specified | Add gradually until spreadable |
| Frosting & Topping | Chocolate syrup | Amount not specified | 6-8 squirts used for swirling |
| Frosting & Topping | Reese’s peanut butter cups, chopped | Amount not specified | Divided, half for swirl and half for topping |
Quick honesty check: the source recipe doesn’t give exact quantities for the powdered sugar or chocolate syrup, so you’re working by feel here. Start with a couple cups of powdered sugar and add more until the peanut butter frosting is spreadable but not stiff.
The instructions also call for an additional stick of butter, cup of peanut butter, and quarter cup of milk specifically for the frosting layer, separate from what goes into the batter, so don’t try to stretch one batch of peanut butter across both jobs.
This isn’t a light dessert, and it’s not supposed to be. The combination of peanut butter dessert flavors with chocolate syrup is what makes this different from a plain peanut butter cake or a standard chocolate sheet cake — you’re getting a real peanut butter chocolate cake experience in every bite, not just a hint of it.
How to Make Reeses Peanut Butter Sheet Cake Step by Step
Prep and Batter
- Preheat your oven to 350°F (175°C).
- Grease and flour a 9×13 inch baking pan.
- In a large bowl, cream together 1 cup peanut butter, 8 tablespoons softened butter, and 1 cup granulated sugar until light and fluffy.
💡 Cream the butter, peanut butter, and sugar until the mixture actually lightens in color — that’s your sign the sugar’s aerating the fat properly.
- Beat in the eggs one at a time.
- Mix in the vanilla extract.
- Gradually add the flour and milk alternately, beginning and ending with flour, mixing until the batter is smooth. If you’re using a chocolate cake mix instead, prepare it according to the package directions first, then incorporate the peanut butter, butter, and sugar into that batter.
Pro Tip: Alternating flour and milk instead of dumping them in at once keeps the batter from curdling or turning gritty.
Assemble and Swirl
- Pour half of the cake batter into the prepared baking dish.
- In a separate bowl, blend 1 stick of butter, 1 cup of peanut butter, and 1/4 cup milk with powdered sugar until well mixed and spreadable.
- Spoon half of the peanut butter frosting mixture over the batter in the pan.
- Add 6-8 large squirts of chocolate syrup on top.
- Gently swirl the frosting and chocolate syrup into the batter with a butter knife, making sure the swirls reach the edges and bottom of the pan.
💡 Drag the knife in a figure-eight pattern instead of straight lines — you’ll get more distinct marbling instead of one muddy color.
- Sprinkle half of the chopped Reese’s peanut butter cups over the swirled batter and press them in gently.
Bake and Finish
- Bake for 35-40 minutes, or until a toothpick inserted into the center comes out clean. For two separate layers instead of a sheet cake, bake in two 9-inch round pans for about 30 minutes.
Pro Tip: A toothpick with a few moist crumbs is fine — bake until it comes out clean and you’ve likely dried out the frosting swirls inside.
- Let the cake cool completely on a wire rack before frosting.
- Frost the cooled cake with the remaining peanut butter frosting, more chocolate syrup, and the rest of the chopped Reese’s cups.
Expert Tips for Perfect Reeses Peanut Butter Sheet Cake
Pro Tips for Success
The key to a good swirl pattern is working fast once the frosting and syrup hit the batter — if it sits too long, the layers start to blend instead of marble. For best results, let the cake cool all the way to room temperature before you frost it, because warm cake will just melt the frosting into a puddle. The most common mistake is over-swirling until the whole top turns one brownish color — instead, do six or seven passes with the knife and stop.
Reeses Peanut Butter Sheet Cake works best when the peanut butter and butter are fully softened before creaming, so pull them out of the fridge early. You’ll know the batter is ready when it looks glossy and holds its shape on the spoon instead of running off in a thin stream.
Delicious Variations
For a quick version, skip the homemade peanut butter cake base entirely and use the chocolate cake mix option, which cuts prep time by roughly ten minutes. For a gluten-free version, swap the all-purpose flour for a 1:1 gluten-free baking blend and use a certified gluten-free cake mix if you’re going that route. If you want alternative toppings, chopped peanuts or a drizzle of melted chocolate work in place of extra Reese’s cups if you’re out or want something less sweet on top.
Troubleshooting Common Problems
Problem: The frosting swirl sinks to the bottom instead of staying marbled. Solution: Your frosting is probably too thin — add more powdered sugar until it holds a ribbon shape when you drizzle it off the spoon.
Problem: The cake domes and cracks in the middle. Solution: Your oven’s likely running hot. Check the actual temperature with an oven thermometer and reduce it by 15-20 degrees if needed.
Problem: The center stays gooey even after 40 minutes. Solution: That gooeyness is often just melted Reese’s cup, not batter — test with the toothpick in a spot away from the visible peanut butter cup chunks.
How to Store and Reheat Reeses Peanut Butter Sheet Cake
| Storage Method | Duration | Best Practice |
|---|---|---|
| Room Temperature | Up to 2 days | Cover tightly to keep the frosting from drying out |
| Refrigerator | Up to 5 days | Store in an airtight container, let come to room temp before serving |
| Freezer | Up to 3 months | Wrap individual slices in plastic then foil |
A cold slice straight from the fridge is honestly good on its own, but if you want that just-baked texture back, microwave a piece for 10-15 seconds until the frosting just starts to soften and the chocolate swirl looks slightly glossy again. Don’t microwave longer than that or the Reese’s cups on top turn into a molten mess that spreads everywhere. Leftover crumbs and edge pieces work great crumbled over vanilla ice cream or layered into a quick trifle with whipped cream.
FAQs About Reeses Peanut Butter Sheet Cake
Can I make this Reeses Peanut Butter Sheet Cake ahead of time?
Yes, you can bake the cake up to two days ahead and store it covered at room temperature before frosting it the day you plan to serve it. The frosted cake also holds well in the refrigerator for a day or two if you need extra lead time.
Can I use a different peanut butter cup brand?
Yes, any chopped peanut butter cup works in place of Reese’s, though the flavor and melt will vary slightly by brand. Reese’s cups are called for here because their higher peanut butter ratio holds up well against the chocolate swirl.
Why did my swirl pattern disappear during baking?
This usually happens when the frosting is too thin and sinks into the batter before it sets, or when the knife strokes went too deep and blended everything together. Keep your frosting thick enough to hold a ribbon and limit yourself to six or seven swirling passes.
Can I freeze this cake?
Yes, wrapped individual slices freeze well for up to three months. Thaw them in the refrigerator overnight rather than at room temperature to keep the frosting from separating.
Is there a dairy-free way to make this recipe?
You can substitute dairy-free butter and a plant-based milk for the dairy versions called for in the ingredient list, and most chocolate syrups are already dairy-free. Check your peanut butter cup brand, though, since standard Reese’s cups do contain milk.
Honestly, if you make one sheet cake this year, make it this one. Seriously — the swirl pattern alone gets people asking for the recipe before they’ve finished their first slice, and it travels well if you need to bring dessert somewhere. Pin it now so you don’t lose track of it, and come back and let me know how your swirls turned out in the comments. I mean it, I read every one.
Reese’s Peanut Butter Sheet Cake with swirls of peanut butter frosting, chocolate syrup, and chopped Reese’s cups on every gooey, fudgy slice. Pin this one for your next potluck.
For another chocolate and peanut butter combination, try this chocolate peanut butter sheet cake. If you’re looking for more easy sheet cake ideas, the cinnamon roll poke cake and the 4-ingredient yogurt cake are both worth a look.
Reese’s Peanut Butter Sheet Cake
Equipment
- 9×13 inch baking pan
- Large mixing bowl
- Wire rack
- Butter knife
Ingredients
Main Batter
- 1 cup creamy peanut butter room temperature blends easier
- 8 tablespoons unsalted butter softened
- 1 cup granulated sugar
- 4 large eggs add one at a time
- 1 teaspoon pure vanilla extract
- 1 cup all-purpose flour
- ½ cup milk
Optional Chocolate Base
- 1 box chocolate cake mix for a chocolate cake version, use instead of homemade peanut butter batter
Frosting & Topping
- 1 stick unsalted butter for the frosting
- 1 cup creamy peanut butter for the frosting
- ¼ cup milk for the frosting
- powdered sugar amount not specified; add gradually until spreadable
- 6-8 squirts chocolate syrup used for swirling, plus more for topping
- Reese’s peanut butter cups, chopped divided, half for swirl and half for topping
Instructions
- Preheat your oven to 350°F (175°C).
- Grease and flour a 9×13 inch baking pan.
- In a large bowl, cream together 1 cup peanut butter, 8 tablespoons softened butter, and 1 cup granulated sugar until light and fluffy. Cream until the mixture actually lightens in color, which shows the sugar is aerating the fat properly.
- Beat in the eggs one at a time.
- Mix in the vanilla extract.
- Gradually add the flour and milk alternately, beginning and ending with flour, mixing until the batter is smooth. If using a chocolate cake mix instead, prepare it according to package directions first, then incorporate the peanut butter, butter, and sugar into that batter. Alternating flour and milk instead of dumping them in at once keeps the batter from curdling or turning gritty.
- Pour half of the cake batter into the prepared baking dish.
- In a separate bowl, blend 1 stick of butter, 1 cup of peanut butter, and 1/4 cup milk with powdered sugar until well mixed and spreadable.
- Spoon half of the peanut butter frosting mixture over the batter in the pan.
- Add 6-8 large squirts of chocolate syrup on top.
- Gently swirl the frosting and chocolate syrup into the batter with a butter knife, making sure the swirls reach the edges and bottom of the pan. Drag the knife in a figure-eight pattern for more distinct marbling instead of one muddy color, doing about six or seven passes and stopping before it blends into one color.
- Sprinkle half of the chopped Reese’s peanut butter cups over the swirled batter and press them in gently.
- Bake for 35-40 minutes, or until a toothpick inserted into the center comes out clean. For two separate layers instead of a sheet cake, bake in two 9-inch round pans for about 30 minutes.
- Let the cake cool completely on a wire rack before frosting, since warm cake will melt the frosting into a puddle.
- Frost the cooled cake with the remaining peanut butter frosting, more chocolate syrup, and the rest of the chopped Reese’s cups.
