Soft and Chewy Peanut Butter Brownies are the kind of bar I make when I want a rich chocolate brownie but also want that creamy peanut butter flavor in the same bite. They’re fudgy, not cakey, with a swirl that stays soft even after the brownies cool.
For me, the best part is the texture: chewy edges, a fudgy center, and a peanut butter layer that tastes like a simple frosting baked right in. I also like that this recipe uses cocoa powder, so it’s easy to keep the pantry stocked for it.
I make these for weekends, cookie trays, and casual get-togethers where brownies make more sense than cake. They slice into clean squares once cooled, which makes them easy to serve without fuss.
Why You’ll Love This Recipe
Soft and Chewy: These stay tender and chewy, with that classic brownie bend when you bite in.
Deep Chocolate Flavor: Cocoa powder gives you a rich chocolate base without needing fancy ingredients.
Peanut Butter Swirl: The swirl bakes up creamy and sweet, and you get peanut butter in nearly every slice.
One-Bowl Friendly: The brownie batter comes together quickly, and you don’t need a mixer.
Easy to Customize: Chocolate chips, peanut butter chips, or chopped peanuts all work depending on what you like.
Ingredients You’ll Need
Brownie Batter
- Unsalted butter: Melted butter keeps the brownies fudgy. I like unsalted so you can control the salt level.
- Granulated sugar: This gives you that classic brownie sweetness and helps make the top a little shiny.
- Light brown sugar: Brown sugar is where some of the chew comes from. Dark brown works too if that’s what you have.
- Eggs: Room temp mixes in more smoothly, but cold eggs are fine in a pinch.
- Vanilla extract: Don’t skip it. It makes the chocolate taste more rounded.
- Unsweetened cocoa powder: I use regular unsweetened cocoa here. Dutch-process is fine too and will taste a little smoother.
- All-purpose flour: Regular flour is all you need. Don’t overmix once it goes in or the brownies can get tough.
- Fine salt: Just enough to keep the chocolate from tasting flat.
- Semisweet chocolate chips (optional): I like these for little pockets of chocolate, but the brownies are still great without them. Peanut butter chips are a fun swap.
Peanut Butter Swirl
- Creamy peanut butter: The standard creamy jar kind works best for a smooth swirl. If you use natural peanut butter, make sure it’s well stirred and not runny.
- Unsalted butter: A little melted butter helps the swirl stay creamy and easier to dollop.
- Powdered sugar: This sweetens and thickens the swirl so it doesn’t just disappear into the batter.
- Vanilla extract: A small amount makes the peanut butter taste more dessert-like.
- Milk: You’ll only need a little, just to get the swirl mixture thick but pourable.
- Salt (optional): I add a pinch if the peanut butter is on the sweeter side. It sharpens the flavor.
Recipe Instructions
- Preheat the oven: Heat the oven to 350°F. Line an 8-inch square pan with parchment paper and lightly grease it.
- Mix the sugars: Whisk the melted butter with the granulated sugar and brown sugar until glossy.
- Add the eggs: Whisk in the eggs and vanilla extract until smooth and well combined.
- Add cocoa powder: Fold in the cocoa powder until the batter looks evenly mixed.
- Add flour and salt: Fold in the flour and salt just until you don’t see dry streaks.
- Add chocolate chips: Fold in the semisweet chocolate chips if you’re using them.
- Spread the batter: Spread the brownie batter evenly in the prepared pan.
- Mix the peanut butter swirl: Stir the peanut butter, melted butter, powdered sugar, vanilla, and enough milk to make a thick, pourable mixture.
- Swirl: Dollop the peanut butter mixture over the brownie batter, then gently swirl with a knife.
- Bake: Bake for 25 to 32 minutes, until the edges are set and a toothpick inserted near the center comes out with moist, fudgy crumbs.
- Cool: Let the brownies cool completely in the pan before slicing into squares.
Some of my tips!
This is the part that really makes a difference. If you only read one section, make it this one because this is where I share the little trick that helps the recipe turn out so well.
Recipe Tips & Tricks
Use parchment paper. It makes lifting the brownies out easy, and it helps you get cleaner edges when you slice.
Stop mixing as soon as the flour disappears. Overmixing is the fastest way to lose that soft, fudgy texture.
Keep the peanut butter swirl thick. If it’s too thin, it sinks into the batter instead of sitting on top for a real swirl. Add milk slowly and stop as soon as it loosens up.
Underbake slightly for extra chew. Pull them when the center toothpick has moist crumbs, not wet batter. They set more as they cool.
Cool completely before slicing. Warm brownies cut messy, and the swirl can smear. A fully cooled pan gives you neat squares.
Make some touches!
There are plenty of easy ways to serve this depending on the occasion. Keep it simple, or add a few small touches to make it feel a little more special.
Serving Suggestions
- Milk: A cold glass of milk is classic with these. It’s especially nice if you bake them a touch under for a fudgy center.
- Coffee or espresso: These are really good with coffee, especially if you like a slightly less sweet drink next to a sweet brownie.
- Ice cream: Serve a square with vanilla ice cream on the side. A little chocolate sauce is good too if you want to dress it up.
- Fruit: Fresh strawberries or raspberries are nice with the chocolate-peanut butter combo. I usually just put a handful on the plate.
Save it for later
This section covers how to store leftovers and what parts of the recipe you can prepare ahead of time.
Storage and Make Ahead
Store brownies covered at room temperature for 2 to 3 days. I usually keep them right in the pan with foil over the top, or move slices to an airtight container.
Store leftovers covered in the fridge for up to 4 days. They get a little firmer when chilled, which some people actually prefer for cleaner, denser bites.
You can freeze individual portions or freeze the whole slab (well wrapped). Thaw in the fridge overnight or on the counter until soft again.
If you like them warm, microwave a square for a few seconds. Just keep it brief so the peanut butter swirl doesn’t get oily.
A few quick answers
This section covers a few extra details that may help before you head to the recipe card.
Recipe FAQs
How do I know when these brownies are done?
Look for set edges and a center that doesn’t jiggle when you gently move the pan. A toothpick inserted near the center should come out with moist crumbs, not wet batter.
Can I use natural peanut butter for the swirl?
You can, but it works best if it’s well stirred and thick. If it’s very runny, the swirl can spread too much and look oily.
Can I double this recipe in a 9×13 pan?
Yes. Double the ingredients, bake in a 9×13-inch pan, and plan to add about 5 to 10 minutes to the baking time. Still use the toothpick test near the center.
Do I have to use chocolate chips?
No. They’re optional, and the brownies are still plenty chocolatey without them. You can also swap in peanut butter chips or chopped peanuts if you want more crunch.
Why did my swirl sink into the brownie batter?
The swirl mixture was probably too thin, or it got over-swirled. Keep it thick and pourable, dollop it on top, and do just a few gentle passes with the knife.
You might also like
Before you go, take a look at a few other recipes below the recipe card. They use similar ingredients in a different way and are worth saving too.
MORE DINNER RECIPES TO TRY
Soft and Chewy Peanut Butter Brownies
INGREDIENTS
Brownie Batter
- 1/2 cup unsalted butter melted
- 1 cup granulated sugar
- 1/2 cup packed light brown sugar
- 2 large eggs room temperature
- 2 tsp vanilla extract
- 3/4 cup unsweetened cocoa powder
- 3/4 cup all purpose flour
- 1/2 tsp fine salt
- 1/2 cup semisweet chocolate chips optional.
Peanut Butter Swirl
- 1/2 cup creamy peanut butter
- 2 tbsp unsalted butter melted
- 1/2 cup powdered sugar
- 1/2 tsp vanilla extract
- 1 to 2 tbsp milk as needed
- pinch of salt optional.
INSTRUCTIONS
Pan and Oven
- heat oven to 350 degrees F
- line an 8 inch square pan with parchment and lightly grease.
Make Brownie Batter
- whisk melted butter with granulated sugar and brown sugar until glossy
- whisk in eggs and vanilla until smooth
- fold in cocoa powder then flour and salt just until combined
- fold in chocolate chips if using
- spread batter evenly in pan.
Make Swirl and Bake
- stir peanut butter with melted butter powdered sugar vanilla and enough milk to make a thick pourable mixture
- dollop peanut butter mixture over brownie batter and gently swirl with a knife
- bake until edges are set and a toothpick inserted near the center comes out with moist fudgy crumbs 25 to 32 minutes
- cool completely before slicing for clean squares.
