Chocolate Peanut butter lovers will love these fudgy brownies with swirls of peanut butter! Even better? They are a box brownie mix hack. A few extra ingredients turns ordinary brownies into an extraordinary dessert with no work from you.
Everyone needs a fast dessert recipe that’s extra special. The secret weapon recipe you can bake up without much notice to the delight of those enjoying it.
These chewy peanut butter brownies are that recipe. Just a few extra ingredients make such a difference!
Choose any favorite brownie mix, regular or gluten-free, to transform into a rich, chocolatey dessert with a peanut butter flavor. They are as delicious as fully homemade brownies but can be whipped up so quickly.
This chocolate peanut butter brownies recipe is extra rich so we find cutting them into small brownies is just right.
Why you’ll love this recipe
These peanut butter swirl brownies have loads of nutty peanut butter AND chocolate in every bite
- Fudgy inside chewy texture outside
- Easy recipe jump started by using a mix and embellishing
- Rich chocolatey dessert
- Regular or gluten-free brownies can be made
Recipe Ingredient Notes
Brownie mix. Use either regular or gluten-free brownie mix. You’ll need the ingredients called for on the brownie mix package as well.
Peanut butter. Use smooth creamy peanut butter not crunchy peanut butter. Do not use creamy natural peanut butter with oil that separates. Gently melt the peanut butter in the microwave or stove top before starting. This allows peanut butter filling to be more easily spread, inside and on top of the brownies.
Chocolate chips. We used semi-sweet chocolate chips but any type can be used. Milk chocolate chips or dark chocolate chips. It’s a very rich mixture so semi-sweet adds just enough extra chocolate!
How to make Peanut Butter Brownies – Step-by-Step
STEP 1. Preparation
Preheat the oven according to the brownie package instructions. Prepare the 9-inch by 9-inch baking pan by lining with parchment paper or aluminum foil. Leave some parchment overhanging the sides of the pan to lift out the brownies.
STEP 2. Make batter and assemble
In a large bowl prepare the brownie mix according to mix instructions (add the dry ingredients to any ingredients called out on the package). Stir in the peanut butter chips and chocolate chips to combine (photo 1).
Spoon half the the batter into the prepared pan. Drizzle half of the melted peanut butter on top of it (photo 2).
Spoon on the remaining brownie batter. Drizzle four lines of the remaining peanut butter on top of the brownie batter and drag a knife through it for a marbled effect (photo 3).
STEP 3. Bake
Bake brownies in the oven for the suggested time on the mix box (photo 4). Cool completely on a wire rack before slicing and serving.
Remove the brownies from the pan with the parchment paper and cut with a sharp knife
Use a spatula to spread the mix. Thicker mixes need some help to spread in the pan. Use a silicon or rubber spatula to move the mix to cover the pan or the peanut butter layer.
Use creamy peanut butter without added sugar. The chewy brownies are already very rich and sweet. If possible use a creamy peanut butter that does not have sugar added.
Do not overbake. To keep the peanut butter swirl brownies super fudgy chocolate brownies do not over bake!
How to Store
Brownies are best stored at room temperature. Place cut brownies in an airtight container (or seal the pan well with plastic wrap) and store for up to 5 days; brownies are best 1 to 2 days after baking. Uncut brownies will stay moist longer.
They can also be stored in the refrigerator but seal well as they can dry out.
Freezing: Place cut brownies in an airtight freezer proof container for up to 3 months. Thaw in the refrigerator.
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Peanut Butter Brownies
- 1 box brownie mix regular or gluten-free, with ingredients called for on the box mix
- ½ cup peanut butter chips
- ½ cup chocolate chips
- 1/3 cup peanut butter melted
- Preheat oven according to brownie package instructions and line a 9-inch square baking pan with foil or parchment paper leaving some overhanding the sides of the pan (for easy lift out). Spray with non-stick spray.
- Add the peanut butter chips and chocolate chips to the brownie batter and stir to combine.
- Spoon half the batter in the prepared pan and spread to cover the bottom of the pan. Drizzle half the peanut butter over the top.
- Top with remaining brownie batter smooth to cover the brownie layer.
- Drizzle four lines of the remaining peanut butter on top of the brownie, then drag a knife across the lines to create a marble effect.
- Bake the brownies in the preheated oven according to package instructions and allow to cool completely before slicing and serving.
- Remove the brownies from the pan with the foil or parchment. Cut into squares.