Soft and Chewy Soft Peanut Butter Brownies are my go-to when I want a pan of brownies that stays fudgy, not cakey, with that familiar peanut butter + chocolate combo.
The brownie base is deep and cocoa-forward with a soft, chewy bite, and the swirl on top gives you little pockets of creamy peanut butter in every square. I like this version because it’s rich but still easy to slice and serve once it cools.
These are especially good for a cookie tray, a casual weekend dessert, or when I need a simple baked treat that holds up well for sharing.
Why You’ll Love This Recipe
Soft and Chewy: The centers stay tender and dense, with that classic brownie chew instead of a fluffy cake texture.
Rich Cocoa Base: Using cocoa powder gives the brownies a deep chocolate flavor that tastes like a real brownie, not a chocolate snack cake.
Peanut Butter Swirl: The swirl bakes into creamy ribbons, so you get peanut butter flavor without turning the whole pan into blondies.
One Bowl Batter: The brownie batter comes together quickly with just a whisk and a spatula, which is exactly what I want on busy days.
Easy to Customize: Add chocolate chips, swap in peanut butter chips, or toss chopped peanuts on top if you want more texture.
Ingredients You’ll Need
Brownie Batter
- Unsalted butter: Melted butter makes this batter simple and gives you that fudgy texture. If you use salted butter, just go a little lighter on added salt.
- Granulated sugar: This gives the brownies that shiny, crackly top when you whisk it well with the warm butter.
- Light brown sugar: I like using brown sugar here for extra chew and a slightly deeper sweetness. Dark brown sugar works too if that’s what you have.
- Eggs: Room-temperature eggs mix in more smoothly, so the batter stays glossy instead of lumpy.
- Vanilla extract: Don’t skip it. It makes the chocolate taste more rounded.
- Unsweetened cocoa powder: Regular unsweetened cocoa is perfect here. Dutch-process works too, but the flavor will be a little darker and smoother.
- All-purpose flour: I use regular flour here. Measuring carefully helps keep the brownies from going cakey.
- Fine salt: A little salt keeps the chocolate and peanut butter from tasting flat.
- Chocolate chips (optional): I use semisweet most of the time, but milk chocolate is fine if you like things sweeter. They make the brownies a bit gooier.
Peanut Butter Swirl
- Creamy peanut butter: Creamy is easiest to swirl and gives you clean ribbons. Natural peanut butter is fine, but it needs to be well stirred and not runny.
- Powdered sugar: This sweetens and thickens the swirl so it sits nicely on top instead of disappearing into the batter.
- Milk: Just enough to loosen the peanut butter so it drizzles and swirls without tearing the brownie layer.
- Vanilla extract: A small amount makes the swirl taste more like a peanut butter frosting stripe than plain peanut butter.
Recipe Instructions
- Preheat the oven: Heat the oven to 350°F. Line an 8-inch square pan with parchment paper, then lightly grease the parchment and sides.
- Whisk the butter and sugars: In a mixing bowl, whisk the melted butter with the granulated sugar and brown sugar until it looks glossy and well blended.
- Add the eggs: Whisk in the eggs and vanilla until the batter looks smooth and a little thicker.
- Add the cocoa: Fold in the cocoa powder until you don’t see dry streaks.
- Add the flour and salt: Fold in the flour and salt just until combined. Stop as soon as the flour disappears so the brownies stay fudgy.
- Add chocolate chips: If you’re using chocolate chips, fold them in evenly.
- Spread the batter: Scrape the batter into the prepared pan and spread it into an even layer.
- Mix the peanut butter swirl: In a small bowl, stir the peanut butter with powdered sugar, milk, and vanilla until smooth and drizzle-able.
- Swirl: Drizzle the peanut butter mixture over the batter. Use a knife to gently swirl it for a marbled look, without mixing it fully in.
- Bake: Bake for 28 to 35 minutes, until the edges are set and the center looks just set. A toothpick should come out with moist crumbs, not wet batter.
- Cool: Let the brownies cool completely in the pan before slicing so you get clean 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
Don’t overmix once the flour goes in. Stir just until you no longer see dry flour. Overmixing is what pushes brownies toward a cakier texture.
Use natural peanut butter only if it’s thick. If it’s runny, the swirl can sink and blend into the batter instead of staying on top. If it’s the natural kind, stir it really well and make sure it’s not separated.
Underbake a little if you like a softer center. I pull these when the middle looks just set and the toothpick has moist crumbs. The brownies keep setting as they cool.
Cool completely before slicing. Warm brownies are delicious, but they don’t cut cleanly. If you want sharp edges, chill the pan for a bit and wipe your knife between cuts.
Swap the mix-ins if you want. Chocolate chips are optional, and peanut butter chips or chopped peanuts work really well too if you want more peanut flavor or crunch.
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, especially since the cocoa base is rich. I like whole milk, but any kind works.
- Ice cream: Vanilla ice cream on the side is simple and always good. If you want to lean into the peanut butter, try coffee or caramel ice cream.
- Fruit: Fresh strawberries or raspberries are nice with a square of brownie. It keeps the plate from feeling too heavy.
- Extra drizzle: Warm a little peanut butter and drizzle it over the top right before serving. It’s an easy way to dress them up for company.
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 the brownies covered at room temperature for 2 to 3 days. I usually keep them right in the pan with foil over the top, then slice as needed.
For a firmer, chewier texture, store leftovers covered in the fridge for up to 4 days. They’re also easier to cut cleanly when they’re chilled.
You can freeze individual portions if you want them to last longer. Wrap the squares well, then thaw at room temperature or in the fridge when you’re ready to eat one.
If you like them warm, microwave a square for a few seconds. The peanut butter swirl softens up again quickly.
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 brownies are done?
I look for set edges and a center that looks just set, not wet. A toothpick should come out with moist crumbs; if it’s totally clean, they may end up a little drier once cooled.
Can I use natural peanut butter for the swirl?
Yes, as long as it’s well stirred and not runny. If the oil is still separated or the peanut butter is very loose, the swirl can sink and blend into the batter.
Can I make these in a 9-inch pan?
You can, but the brownies will be thinner and will bake faster. Start checking a little early, and expect the centers to set sooner.
Why did my brownies turn out cakey?
The two usual reasons are too much flour or overmixing after the flour goes in. I also find that baking a few minutes too long can push the texture from fudgy to more cake-like.
Can I skip the chocolate chips?
Absolutely. The base is plenty chocolatey without them, and the peanut butter swirl still stands out nicely.
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 Soft Peanut Butter Brownies
INGREDIENTS
Brownie Batter
- 1/2 cup unsalted butter melted
- 1 cup granulated sugar
- 1/2 cup light brown sugar packed
- 2 large eggs room temperature
- 1 tsp vanilla extract
- 3/4 cup unsweetened cocoa powder
- 3/4 cup all purpose flour
- 1/2 tsp fine salt
- 1/2 cup chocolate chips optional.
Peanut Butter Swirl
- 1/2 cup creamy peanut butter
- 2 tbsp powdered sugar
- 1 tbsp milk
- 1/2 tsp vanilla extract.
INSTRUCTIONS
Prepare Pan and Oven
- preheat oven to 350 F
- line an 8 inch square pan with parchment paper and lightly grease.
Mix Batter and Bake
- 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 and do not overmix
- fold in chocolate chips if using
- spread batter evenly in pan
- stir peanut butter with powdered sugar milk and vanilla until smooth and drizzle over batter
- gently swirl with a knife for a marbled look
- bake until edges are set and center looks just set with moist crumbs on a toothpick 28 to 35 minutes
- cool completely before slicing for clean squares.
