Fudgy dark chocolate brownies, marbled with a peanut butter swirl! So quick and easy to make, from scratch! If you like Reese’s, you’ll love these peanut butter brownies.

Stack of peanut butter brownies stuffed and swirled with peanut butter, on a blue background with an orange napkin in the background.

Brownies and bars are so easy to make, and the result is always a huge hit! Some of our favorites include these Simply Perfect Rice Krispie Treats, Caramel Apple Oatmeal Carmelitas, and Oreo Cheesecake Brownie Bars.

But of course, chocolate and peanut butter trumps them all. I don’t know a single person that doesn’t swoon at the mere mention of peanut butter brownies.

Overhead image of peanut butter swirl brownies with text overlay.

This recipe is so easy to make, and the result is so ooey-gooey, fudgy, and peanut buttery! If you know a peanut butter lover, you’ve gotta make them these peanut butter brownies!

HOW DO YOU MAKE PEANUT BUTTER BROWNIES?

It all starts with the best ever brownie recipe. This Simply Perfect Brownies from Scratch recipe is all I ever use.

It’s so easy to make, in just one bowl, and you don’t even need a mixer. Just grab a few simple ingredients from your pantry and stir them all together. It’s incredible just how rich, dark chocolate-y, and fudgy these brownies are.

WHAT KIND OF PEANUT BUTTER SHOULD I USE IN MY PEANUT BUTTER BROWNIES?

Use whatever you have on hand. Creamy peanut butter, crunchy peanut butter, natural peanut butter, or just regular old peanut butter like you ate on your sandwiches as a kid. I am partial to this brand, but truly, anything will work. You could even sub almond butter or any other kind of nut butter.

If you are using a natural nut butter, there are just a few things to be aware of:

  • Be sure to stir it well to blend the oils and solids.
  • The consistency might be a little runnier. This is totally fine and the peanut butter brownies should still bake up perfectly.
  • It will be a little less sweet, so give it a taste and add more powdered sugar if you think it needs it.

Fudgy peanut butter stuffed chocolate brownies on a blue background with peanuts in the background.

HOW LONG SHOULD I BAKE MY PEANUT BUTTER BROWNIES?

You’ll know your peanut butter brownies are done when they’re set around the edges but still soft towards the middle. The toothpick test doesn’t really work that well for this recipe, because the brownies are so fudgy.

I like to bake these in a 9×9-inch square pan. In my oven, they take about an hour.

But you can use a 9×13-inch pan too, and because they’ll bake up thinner they probably won’t need quite as much time. I recommend checking them after about 45 minutes.

They’ll be quite soft in the center while they’re still warm, but as they cool they will firm up. I know it’s torture, but wait until they’re completely cool before you cut into them! You’ll get much nicer squares if you can just be patient!

Ny favorite tool for cleanly cutting brownies is this pastry scraper. Push straight down and wipe the blade clean after each cut. Your squares will be perfect!

My dad loved anything peanut butter, and so does my husband. So whenever I think of Father’s Day, peanut butter desserts are always the first thing to pop into my mind!

Check out my Father’s Day category, for lots more peanut butter and dad-friendly dessert ideas.

And here’s an idea for you: If you really want to take this recipe to the next level, try topping a peanut butter brownie with No-churn Vanilla Ice Cream and drizzling it with Hot Fudge Sauce. Peanut Butter Brownie Sundaes- holy yum!

Horizontal image of peanut butter swirl chocolate fudge brownies made from scratch.

More great brownie recipes on my “Brownies & Bars” Pinterest board!


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3.95 from 20 votes
Stack of peanut butter brownies stuffed and swirled with peanut butter, on a blue background with an orange napkin in the background.
Peanut Butter Brownies
Prep Time
20 mins
Cook Time
50 mins
Cooling Time:
2 hrs
Total Time
1 hr 10 mins
 
Fudgy dark chocolate brownies, marbled with a peanut butter swirl! So quick and easy to make, from scratch! If you like Reese's, you'll love these peanut butter brownies.
Course: Dessert
Cuisine: bar
Keyword: peanut butter brownies
Servings: 18
Calories: 382 kcal
Ingredients
For the peanut butter swirl
  • 3/4 cup peanut butter
  • 1/2 cup powdered sugar
  • 1/4 cup half a stick unsalted butter, melted
  • 3/4 teaspoon kosher salt
For the chocolate brownie batter
  • 2 1/2 cups granulated sugar
  • 1 1/4 cups unsalted butter, melted
  • 1 3/4 cups unsweetened cocoa powder
  • 1/2 teaspoon kosher salt
  • 4 large eggs
  • 1 cup all-purpose flour
  • 2 teaspoons baking powder
  • 1 teaspoon vanilla extract
Instructions
To make the peanut butter swirl:
  1. Stir the powdered sugar, peanut butter, melted butter, and salt together in a medium bowl.
To make the chocolate brownie batter:
  1. Preheat the oven to 325 degrees F, mist a 9x9-inch pan with non-stick spray, and line it with parchment.
  2. Place the sugar, melted butter, cocoa, and salt in a large bowl and stir together until combined.
  3. Stir in the eggs.
  4. Add the flour and baking powder, and mix until smooth.
  5. Stir in the vanilla, then pour half the batter into the prepared pan.
  6. Drop about half the peanut butter swirl mixture in dollops over the surface of the brownie batter. Swirl with the tip of a knife.
  7. Layer the remaining brownie batter on top, and repeat the peanut butter swirl.
  8. Bake for 45 to 60 minutes, or until set around the edges but still soft towards the center.
  9. Cool completely in the pan, then transfer to a cutting board and cut into squares.

Recipe Video

Nutrition Facts
Peanut Butter Brownies
Amount Per Serving
Calories 382 Calories from Fat 207
% Daily Value*
Total Fat 23g 35%
Saturated Fat 12g 60%
Cholesterol 82mg 27%
Sodium 193mg 8%
Total Carbohydrates 44g 15%
Dietary Fiber 4g 16%
Sugars 32g
Protein 6g 12%
* Percent Daily Values are based on a 2000 calorie diet.