My fudgy brownies and Chewy Peanut Butter Cookies are two of my favorite desserts, so it only made sense to bring them together! These Sheet Pan Peanut Butter Brookies have a rich, chocolatey brownie base topped with a soft, chewy peanut butter cookie layer.
They are easy to make, perfect for sharing, and always disappear fast. Whether you’re baking for a party, a potluck, or just because you’re craving chocolate and peanut butter, these bars are hard to resist.
What Are Brookies?
Brookies are a dessert that combines brownies and cookies into one treat. The name comes from putting the words “brownie” and “cookie” together. They can be made with different cookie flavors, but they always have that delicious brownie-and-cookie combination.
Ingredients & Substitutions
- Semisweet chocolate chips: These give the brownies a rich chocolate flavor. Milk chocolate or dark chocolate chips can be used if preferred.
- Vegetable oil: Keeps the brownie layer rich and fudgy. Another neutral oil, like canola oil, will work.
- Sugars: A mix of granulated sugar and brown sugar gives the brownies and cookie layer the right sweetness and texture. Light or dark brown sugar can be used.
- Cocoa powder: Use unsweetened cocoa powder for the best chocolate flavor.
- Butter: Use unsalted butter for the peanut butter cookie layer. If using salted butter, reduce the added kosher salt.
- Peanut butter: Creamy peanut butter works best for a smooth cookie layer. Avoid natural peanut butter, as the texture can vary.
- Eggs: Use room-temperature eggs to help everything mix together evenly.
- Vanilla extract: Adds flavor and balances the chocolate and peanut butter.
- All-purpose flour: Provides structure for both layers. I have not tested this recipe with gluten-free flour.
Tips for the Best Peanut Butter Brookies
- Let the chocolate mixture cool slightly. After melting the chocolate and oil, give it a few minutes to cool before adding it to the batter. This helps keep the eggs from getting too warm.
- Do not overmix the cookie dough. Mix the peanut butter cookie layer just until the flour is incorporated. This keeps the cookie layer soft and tender.
- Don’t worry about making the layers perfect. The peanut butter cookie dough does not need to completely cover the brownie batter. A little brownie showing through creates a pretty marbled look.
- Watch the baking time. The brookies should be set around the edges with a soft center. A toothpick should come out with a few moist crumbs, but no wet batter.
- Let them cool before cutting. It can be tempting to slice into these right away, but letting them cool completely helps the brownie and cookie layers set and gives you cleaner bars.
FAQs
Can I make these brookies in a different pan?
This recipe is based on my Sheet Pan Brownies, which are baked in an 18×13-inch half-sheet pan. If you use a smaller pan, the brookies will be thicker and will need additional baking time. Keep an eye on them and bake until the center is set.
Can I use crunchy peanut butter?
Yes, you can use crunchy peanut butter if you like little bits of peanuts throughout the cookie layer. Creamy peanut butter will give you the smoothest texture.
Can I make the brownie layer and cookie layer separately?
Yes! The brownie and peanut butter cookie layers are delicious on their own, but baking them together creates the perfect mix of fudgy chocolate brownie and soft peanut butter cookie in every bite.
How do I know when brookies are done baking?
The peanut butter cookie layer should look lightly golden, and a toothpick inserted into the center should come out with a few moist crumbs. You do not want wet batter, but a few crumbs are perfect for fudgy brookies.
How to Store Peanut Butter Brookies
Room Temperature: Store brookies in an airtight container at room temperature for up to 3 days. For the best texture, let them come to room temperature before serving if they have been stored in a cooler area.
Freezer: Brookies freeze well! Once completely cooled, cut them into bars and place them in a freezer-safe container or bag. Freeze for up to 3 months. Let them thaw at room temperature before serving.
Sheet Pan Peanut Butter Brookies
Ingredients
Brownie Layer
- 2 ½ cups (455 g) semisweet chocolate chips, divided
- 1 ½ cups (326 g) vegetable oil
- 2 cups (400 g) granulated sugar
- 1 ⅓ cups (266 g) light brown sugar, packed
- 6 large eggs, room temperature
- 4 teaspoons vanilla extract
- 2 cups (250 g) all-purpose flour
- 2 cups (236 g) unsweetened cocoa powder
- 1 teaspoon kosher salt
Peanut Butter Cookie Layer
- ¾ cup (1 ½ sticks / 170 g) unsalted butter, softened
- ¾ cup (150 g) granulated sugar
- ¾ cup (150 g) light brown sugar, packed
- 1 cup (270 g) creamy peanut butter
- 2 large eggs, room temperature
- 2 teaspoons vanilla extract
- 2 cups (250 g) all-purpose flour
- 1 teaspoon baking soda
- ½ teaspoon kosher salt
Instructions
- Preheat the oven to 350°F. Line an 18×13-inch half-sheet pan with parchment paper, leaving an overhang on the sides. Lightly spray the parchment with nonstick cooking spray.
Brownie Layer
- In a large microwave-safe bowl, combine 1 cup of the semisweet chocolate chips and the vegetable oil. Microwave in 20 to 30-second intervals, stirring after each, until the chocolate is melted and smooth. Set aside to cool slightly.
- In the bowl of a stand mixer fitted with the paddle attachment, beat together the granulated sugar, brown sugar, eggs, and vanilla on medium-high speed for 3 to 4 minutes, or until smooth and well combined.
- Reduce the mixer to low speed. Slowly pour in the cooled chocolate mixture and mix just until combined.
- In a separate bowl, whisk together the flour, cocoa powder, and kosher salt. Gradually add the dry ingredients to the wet ingredients, mixing on low speed just until combined.
- Fold in the remaining 1 ½ cups semisweet chocolate chips.
- Spread the brownie batter evenly into the prepared pan, smoothing the top with an offset spatula if needed.
Peanut Butter Cookie Layer
- Without washing the mixer bowl, cream together the butter, granulated sugar, and brown sugar until light and fluffy.
- Add the peanut butter, eggs, and vanilla. Mix until smooth.
- Add the flour, baking soda, and kosher salt. Mix on low speed just until combined.
- Drop spoonfuls of the peanut butter cookie dough over the brownie batter. Gently spread or press the dough into an even layer. It doesn’t have to completely cover the brownie batter; a little brownie showing through creates a marbled look.
- Bake for 30 to 35 minutes, or until the cookie layer is lightly golden brown and a toothpick inserted into the center comes out with a few moist crumbs, but no wet batter.
- Let the brookies cool completely in the pan. Using the parchment overhang, lift them out of the pan and cut into bars.
Did you make this recipe?
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You always use such large pans, but I only have 13 x 9 x 2 pans. How do I adjust the oven temp and baking times if I cut the recipe in half and use 2 pans, one at a time? Because I’m baking them in an air fryer toaster oven.
Hi Sunshine! This particular recipe is specifically a sheet pan recipe, so the 18×13-inch half-sheet pan is intentional. I don’t always use pans this large. 😊
Interestingly, two 9×13-inch pans have the same total surface area as one 18×13-inch sheet pan, so you could divide the full recipe evenly between your two pans rather than cutting the recipe in half. I would keep the recipe temperature at 350°F in a conventional oven. However, I haven’t tested these in an air-fryer toaster oven, and those can bake quite differently, so I can’t give you an exact baking time for your appliance. I would begin checking early and look for the same doneness cues in the recipe: a lightly golden cookie layer and a toothpick with a few moist crumbs but no wet batter.
Can you half the recope
If you only have one 9×13 inch pan? Do you use UK egg sizes?
Hi Jill! Yes! You can halve the recipe and bake it in one 9×13-inch pan. The pan has exactly half the surface area of the 18×13-inch sheet pan used in the full recipe, and fortunately all of the ingredients divide evenly. Keep the oven temperature at 350°F and begin checking around the same time, using the doneness cues in the recipe: the peanut butter layer should be lightly golden and a toothpick should have a few moist crumbs but no wet batter.
And the recipe uses U.S. large eggs, which are approximately equivalent to UK medium eggs.
I have not made these brookies yet, as I am questioning using 2 cups of unsweetened cocoa powder, in addition to the semi sweet chocolate chips. I have never used this much cocoa powder in any recipe. As a matter of fact, I usually buy the can of unsweetened cocoa powder, and I don’t think it even holds 2 cups. Please advise. I would love to make these for a Labor Day picnic. Thank you.
Hi Pat! Yes, the 2 cups of unsweetened cocoa powder is correct. 😊 This is a very large recipe specifically developed for an 18×13-inch half-sheet pan, so the ingredient quantities are much larger than you would see in a typical pan of brownies. The brownie layer alone makes enough batter to cover that entire sheet pan before the peanut butter cookie layer is added. I hope you make them for your Labor Day picnic! Chocolate and peanut butter is always a good choice. ❤️
I see someone else had the same issue I did in that I didn’t want to make nearly a full recipe as written either! I cut everything to 1/3 and baked it in a square pan. It was very good! I think my brownie portion was undercooked but even being undercooked it was delicious. It is very dense and I only eat a little at a time because it is so rich. I will continue to make 1/3 recipe because for my family of 3, anything more would be a LOT! Thanks for the great recipe.