If you’re looking for a dessert that checks all the boxes—rich, fudgy, and packed with peanut butter goodness—these Peanut Butter Brownies are it! Made with a boxed brownie mix and just a few simple ingredients, this is the ultimate shortcut for a seriously good treat.
With creamy swirls of peanut butter on top of chocolatey, gooey brownies, these are like the perfect mash-up of classic brownies and Reese’s peanut butter brownies—only way easier to make.
Ingredients for Peanut Butter Swirl Brownies
This recipe starts with a boxed brownie mix, but the peanut butter twist makes it feel totally homemade.
- 1 box peanut butter brownie mix (any brand)
- 1 egg
- 2 tbsp water
- 2 tbsp vegetable oil
- 2–4 tbsp peanut butter (use the pouch included in the box or your own)
- 8×8-inch square baking tin
- Parchment paper
Want them extra gooey? Add a few extra tablespoons of peanut butter for extra creaminess!
How to Make Easy Peanut Butter Brownies
Step 1: Mix the Batter
In a mixing bowl, combine the brownie mix, egg, water, and oil. Use a whisk or electric mixer to blend until smooth and creamy.
Step 2: Pour and Swirl
Line your 8×8 pan with parchment paper and pour the brownie batter in evenly.
Drizzle the peanut butter over the top in swirls. You can use the packet from the box or add more for a bold peanut butter flavor.
Step 3: Bake
Preheat your oven to 320°F and bake for 15–18 minutes, or until a toothpick inserted in the center comes out mostly clean (a few fudgy crumbs are fine!).
Step 4: Cool and Cut
Let the brownies cool in the pan for a few minutes, then transfer to a cooling rack. Once fully cooled, cut into bite-sized squares and enjoy!
Quick Recipe Info:
- Difficulty: Super easy
- Prep Time: 5–10 minutes
- Bake Time: 15–18 minutes
- Servings: 9–12 brownies
Perfect For:
- Why You’ll Love These Chocolate Peanut Butter Brownies
- A fast shortcut to a fudgy brownie recipe with a gourmet twist
- You can make them as swirly or peanut-buttery as you like
- Perfect for bake sales, parties, or just a sweet snack at home
- Kid-friendly and freezer-friendly
- One of the best brownie recipes with peanut butter out there!
Fun Add-Ins & Variations
- Stir in peanut butter chips or chocolate chips for extra texture
- Top with crushed Reese’s cups before baking for the ultimate peanut butter chocolate brownies recipe
- Drizzle melted chocolate over the cooled brownies for a bakery-style look
- Mix in chopped peanuts for a bit of crunch
Perfect For:
- After-school treats
- Bake sales & potlucks
- Movie night snacks
- Quick brownie bars for any occasion
- Anyone craving brownies with peanut butter chips or a fudgy, gooey swirl
📸 Show Us Your Swirls!
Did you make these peanut butter swirl brownies? We want to see! Tag #BiteSizedFun on Instagram or Pinterest so we can admire your chocolatey creations.
More Brownie Fun to Try Next:
- Coming Soon…
These easy peanut butter brownies are rich, chocolatey, and so satisfying with every bite. Whether you’re new to baking or just want something quick and crowd-pleasing, this swirl brownie recipe is the sweet fix you’ve been looking for.
One More Thing!
This recipe is part of our collection of easy dessert recipes. Check it out!
Peanut Butter Brownies
Ingredients
- 1 Box peanut butter brownie mix any brand
- 2-4 tbsp peanut butter pouch was included with my cake box
- 1 egg
- 2 tbsp water
- 2 tbsp vegetable oil
Instructions
- Mix cake with water, egg and oil. Use an electric mixer or whisk and blend until smooth.
- Place a parchment paper in your square tin and pour the mixture evenly.
- Drizzle peanut butter over the mixture, you can add as little or as much you like. I sometimes prefer to add 2 spoons extra to make brownies creamier.
- Preheat oven to 320F and bake for 15-18 minute or until inserted toothpick comes clean.
- Leave it to cool it down on a cooling rack then cut into little squares. Enjoy!
