Peanut Butter Swirl Brownies
These fudgy and chewy peanut butter swirl brownies are one of our favorite homemade brownie recipes!
This posts includes lots of tips for making peanut butter brownies at home – like making them fudgier or chewier, plus freezing them for later. We also tested this recipe multiple times and found it makes AWESOME gluten free brownies!
After I spent a whole week perfecting our homemade brownie recipe, (I went through sooo much butter and chocolate) I knew I needed to make a variation with peanut butter. I am a big fan of reese’s peanut butter cups so naturally this brownie recipe has become a favorite!
How would I describe this peanut butter swirl brownie?
It’s fudgy, but not “I’m eating a molten chocolate fudgy brownie”. It’s got that crispy and shiny outside. And it’s slightly chewy (and can be more chewy if you bake it longer). Then there’s the ribbon of peanut butter swirled in. It’s not overpowering, but adds a nice pizzazz to a chocolate brownie!
How to make chewy peanut butter brownies
I originally started with a brownie that was really heavy on melted chocolate. Lots of melted chocolate is what makes a brownie super fudgy. But in order to achieve a chewier texture, I cut back on the amount of melted chocolate and increased the amount of cocoa powder.
How to make a brownie with a crispy, shiny top
After consulting many sites, beating the sugar with the eggs is what I discovered works the best to get the crispy, shiny top on the brownies. I suppose it’s not that simple – the amount of granulated sugar in the recipe plays an important part too.
Butter VS. Oil in brownies
For my personal tastes, I found that my optimal brownie uses a combination of butter and vegetable oil. Butter enhances the natural chocolate flavor but oil helps to produce a chewier brownie.
How many eggs should I put in homemade brownies?
Lastly, the egg debate. I found that I liked 2 eggs plus an additional egg yolk. The additional egg yolk adds more fat, creating a fudgier brownie.
Should I use a glass or metal pan?
I used a glass 8×8 inch baking pan because that’s what I have in my kitchen! You can use a metal pan and I would recommend decreasing the baking time by 5 minutes. Metal pans heat up faster and can produce chewier brownies.
What type of gluten free flour should I use to make gluten free peanut butter swirl brownies?
I recommend and tested this recipe multiple times with King Arthur’s Measure for Measure All Purpose Gluten Free Flour.
How to make peanut butter swirl brownies
This recipe can be separated into 2 parts – the brownie batter and the peanut butter swirl.
For the brownie batter it’s key to not overmix the dry ingredients into the batter. Mix BY HAND just until the majority of the flour is no longer visible.
For the peanut butter swirl..
heat the peanut butter until it’s liquidy. Then mix in the powdered sugar.
I found it’s best to pipe the peanut butter layer over the brownie batter. That way you end up with nice, beautiful swirls instead of big blobs. Caution: DO NOT over swirl! If you mix the batter too much, it will become muddled and not have defined swirls.
Want more peanut butter in these brownies? Increase the amount of peanut butter to 1/2-3/4 cup. Add all but 1/2 cup of brownie batter to the pan. Pipe in the peanut butter layer, then go back and add in the remaining brownie batter. Swirl and bake.
Can I double this recipe?
Yes! If you want to bake these brownies in a 9×13 inch pan, double the recipe. Bake for 29-35 minutes.
How to cut brownies cleanly
To get really nice clean brownie squares, I like to refrigerate my brownies for at least 30 minutes before cutting. Then I use a long 8 inch chef’s knife to cut them. But here’s the MOST IMPORTANT TIP —> wipe the knife CLEAN between each cut. Yes, it’s annoying, but it works!
Can I make brownies ahead of time and freeze them?
Yes! Make the brownies and allow them to cool completely. Cut them into squares, wrap 4 at a time in aluminum foil (wrap well) and store in a freeze ziplock bag for up to 3 months. To thaw, place in the fridge over night.
More peanut butter desserts
- Mini Peanut Butter Cheesecakes
- No Bake Peanut Butter Cup Pie
- Peanut Butter Sheet Cake
- Reese’s Pieces Peanut Butter Cookies
Peanut Butter Swirl Brownies
- ¾ cup properly measured all purpose flour OR gluten free flour I recommend King Arthur’s GF Measure for Measure Flour
- ½ tsp salt
- ⅓ cup unsweetened cocoa powder
- 2 oz unsweetened chocolate chopped
- 8 tbsp unsalted butter, cubed 1 stick
- 1 ¼ cups sugar
- 2 large eggs
- 1 large egg yolk
- ¼ cup vegetable oil
- 1 tsp vanilla extract
Peanut butter swirl
- ⅓ cup creamy peanut butter
- 2 tbsp powdered sugar
- Preheat the oven to 350º F. Line a 8×8 or 9×9 inch pan with aluminum foil or parchment paper. Spray lightly with non-stick cooking spray.
- In a mixing bowl, combine the properly measured flour, salt and cocoa powder. Stir together with a spoon until mixed. Set aside.
- In a small saucepan over low heat, combine the chopped unsweetened chocolate and cubed butter. Stir occasionally until it’s fully melted, about 5 minutes.
- Meanwhile, in a larger mixing bowl, beat the sugar and eggs plus additional egg yolk with an electric mixer for 1 minute, until the mixture is pale yellow and doubled in volume.
- Once the chocolate is melted, pour it into the egg mixture. Then add the vegetable oil and vanilla extract. Stir with a spatula to combine.
- Spoon the flour mixture into the wet ingredients, mixing with a spatula just until combined. Do not continue to mix the batter once you can no longer see flour.
- Transfer the batter to the prepared pan and smooth. Set aside.
- Heat the peanut butter for 15-30 seconds until it’s more liquidy. Mix in the powdered sugar. Transfer the peanut butter mixture to a piping bag or ziplock bag with corner cut off.
- Pipe the peanut butter filling in a grid pattern, then use a butter knife and drag it across the grid to create swirls.
- Bake for 33-35 minutes (glass pan) 30-33 minutes (metal pan) or until a toothpick inserted in the center comes out clean. For a chewier, less fudgy brownie, bake for 36-40 minutes in a glass pan or 34-38 minutes in a metal pan.
- To get really nice clean brownie squares, I like to refrigerate my brownies for at least 30 minutes before cutting. Then I use a long 8 inch chef’s knife to cut them. But here’s the MOST IMPORTANT TIP: wipe the knife CLEAN between each cut. Yes, it’s annoying, but it works!