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These peanut butter swirl brownies are rich, fudgy, and just the right amount of indulgent. With deep chocolate flavor and ribbons of creamy peanut butter swirled throughout, they’re the kind of dessert that feels special without being complicated. Using boxed brownie mix makes them super easy!
Brownies are one of my favorite desserts. I mean, who can resist?! Be sure to try these Cream Cheese Brownies and Brookies too.
Why you’ll love these brownies with peanut butter swirl!
Who knew that using a boxed brownie mix would make brownies this good?! I have all kinds of ways to make boxed brownie mix taste better, but I think adding a ribbon of peanut butter might just be my favorite trick!
Fudgy and chewy, these peanut butter swirl brownies taste like a bakery-worthy recipe and it can be your secret that it all starts with a simple box of brownie mix!
- A brownie for Reese’s lovers: Deeply fudgy brownies with creamy peanut butter in every bite — yum! (You’ll also love these Peanut Butter Cup Brownies.)
- Easier than stuffed brownies: No shaping or sealing required!
- Any anytime kind of treat: It’s perfect for casual baking, parties, or dessert trays.
- Kid-approved: Not only will your kids love eating them, they’ll love helping make them too!
Table of Contents
Ingredients You Need
You just need a handful of ingredients to make this peanut butter brownie recipe!
See recipe card below this post for ingredient quantities and full instructions.
- Brownie mix – Choose your favorite brand of brownie mix to use.
- Ingredients required for the brownie mix (usually eggs, oil, and water) – Be sure to read the back of the brownie box before leaving the store so that you have everything you need.
- Creamy peanut butter – Chunky could work, but it adds a bit of texture and can be harder to mix! For the best results, avoid natural varieties as they tend to separate and can cause your brownies to become runny.
- Powdered sugar – To sweeten the peanut butter ribbon.
Variations
- You can use almond butter or cashew butter in place of the peanut butter.
- Make this recipe nut-free by adding sunflower seed butter in place of peanut butter.
- Use crunchy peanut butter for added texture.
How To Make Peanut Butter Swirl Brownies
- Make the brownie mix: Prepare the brownie mix according to the box directions. Mix until smooth.
- Transfer to pan: Pour the brownie batter into the prepared pan, spreading it out evenly.
- Add the peanut butter: Dollop spoonfuls of the peanut butter mixture on top of the batter.
- Bake: Swirl the peanut butter into the batter. Bake at the time and temperature listed on the box. Remove the brownies from the oven, and let them cool in the pan for about 30 minutes before cutting.
How to Store Baked Brownies
Once cooled, leftover brownies can be transferred to an airtight container and stored at room temperature for up to 3 to 4 days or in the refrigerator for up to 1 week.
Frequently Asked Questions
The toothpick test is the best way to know. Once the baking time has passed, insert a clean toothpick into the center of the brownies. If the toothpick comes out clean or with just a few moist crumbs, the brownies are done baking and ready to take out of the oven.
Yes! To freeze, wrap individual brownies in aluminum foil, and transfer them to a sealable bag. They will stay fresh in the freezer for up to 2 to 3 months. To serve, allow them to thaw in the fridge overnight, and enjoy.
You need to pay close attention to the baking time. If you overbake the brownies, they will be dry and crumbly.
While I’m obsessed with this brownie recipe like it is, you can easily add a little bit of cocoa powder, espresso powder, chopped nuts, or even chocolate chips! Mix and match different flavor variations to make your brownies unique each and every time!
Yes, but make sure it’s well-stirred and not too oily so it swirls smoothly.
More Delicious Brownie Recipes
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Christmas
Christmas Tree Brownies
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Peanut Butter Swirl Brownies
Equipment
- 9×9 inch baking pan
- Parchment paper or cooking spray
- Large mixing bowl
- Microwave safe bowl
- Wire Rack
- Knife for cutting brownies
Ingredients
- brownie mix choose your favorite brand
- ingredients listed on the brownie box
- ½ cup peanut butter creamy
- ¼ cup powdered sugar
- ½ teaspoon vanilla extract
Instructions
- Preheat the oven according to the brownie mix box instructions.
- Line the 9X9 brownie pan with parchment paper. You can also grease it.
- Make the brownie mix according to the box directions. Mix until smooth.brownie mix, ingredients listed on the brownie box
- Add the brownie mix to the pan and spread it out evenly.
- Add the peanut butter to a microwave-safe bowl and heat it for 20 seconds. Stir in the powdered sugar and vanilla until it is nice and smooth.½ cup peanut butter, ¼ cup powdered sugar, ½ teaspoon vanilla extract
- Drop the peanut butter mixture onto the brownie batter by spoonfuls.
- Using a butter knife, swirl the peanut butter and brownie mixture. You can also use a toothpick to do this.
- Put the pan in the oven and bake for the time listed on the box.
- Once the time has passed, remove the brownies from the oven and let the pan cool for about 30 minutes.
- Once the cooling time has passed, move the brownies to a wire rack to cool for about 30 more minutes.
- Cut and serve.
Notes
- Warm the peanut butter slightly. This helps it swirl more smoothly if it’s cold in your kitchen!
- Don’t over-swirl. A few gentle passes make the prettiest pattern
- Let brownies cool before slicing. This will give them clean edges.
Such an easy way to elevate boxed brownies. My family loves chocolate peanut butter and these were so easy!