From time to time, I like to make brownies that are a little more indulgent than usual, but making them with peanut butter in the mix is my favorite twist because it adds flavor and a creamy texture that chocolate alone can’t give. If you are a chocolate lover with a soft spot for peanut butter, these Peanut Butter Swirl Brownies are going to become your new obsession. I also love the look of the swirl; it makes the brownies look homemade and special, like you put extra effort into them, even when the recipe is easy and quick. 

They are rich, fudgy, and perfectly sweet with a creamy peanut butter swirl running through each square. The texture is just the right balance of dense and soft, while the peanut butter adds a nutty, slightly salty contrast that makes every bite irresistible. The combination of chocolate and peanut butter feels like the ultimate comfort food, perfect for sharing with family or enjoying with a cup of coffee.

I have been making these brownies for years, and I use simple ingredients that are easy to find in any kitchen. I always melt the butter slowly to avoid cooking the eggs and make the batter smooth, and I take the time to swirl the peanut butter gently for that beautiful marbled look. I also always let the brownies cool completely before slicing; it makes them look cleaner and keeps the swirl intact.

You can serve these brownies on their own, and they’re perfect for lunchboxes or as an afternoon treat. Some people like to add a scoop of vanilla ice cream or drizzle a little chocolate sauce over the top. They also pair wonderfully with a glass of cold milk, a cup of hot chocolate, or even a warm cup of coffee to make a cozy snack.

Its Perfect For:

• Afternoon tea or coffee breaks
• Birthday parties and special celebrations
• School bake sales or lunchbox treats
• Quick desserts when friends drop by
• Cozy nights in with a movie

Ingredients

• 1/2 cup (115g) unsalted butter
• 1 cup (200g) granulated sugar
• 2 large eggs
• 1 teaspoon vanilla extract
• 1/3 cup (40g) unsweetened cocoa powder
• 1/2 cup (65g) all-purpose flour
• 1/4 teaspoon salt
• 1/4 teaspoon baking powder
• 1/3 cup (80g) creamy peanut butter
• 2 tablespoons powdered sugar (optional, for easier swirling)

Kitchen Equipment You’ll Need

• 8×8-inch baking pan
• Mixing bowls (small and medium)
• Whisk and spatula
• Knife or skewer for swirling
• Parchment paper for lining the pan
• Measuring cups and spoons
• Cooling rack

How to Make Peanut Butter Swirl Brownies

Step 1

Prepare the pan: Preheat your oven to 350°F (175°C). Line an 8×8-inch (20×20 cm) baking pan with parchment paper, leaving a little overhang for easy removal. This ensures the brownies won’t stick and makes slicing easier later.

Step 2

Melt the butter: In a small saucepan over low heat, melt the butter completely. Remove from heat and let it cool slightly. This will help the batter mix smoothly without cooking the eggs when added.

Step 3

Mix the brownie batter: In a medium bowl, whisk together the sugar and eggs until light and slightly fluffy. Add vanilla extract and the melted butter, stirring until fully incorporated. Gradually sift in cocoa powder, flour, salt, and baking powder. Fold gently until the mixture is smooth and thick. Avoid overmixing to keep the brownies tender.

Step 4

Prepare the peanut butter swirl: In a small bowl, mix the peanut butter with powdered sugar (if using) until smooth and slightly thinner in consistency. This helps the swirl spread more easily throughout the batter.

Step 5

Layer and swirl: Pour half of the brownie batter into the prepared pan and smooth it evenly. Drop spoonfuls of the peanut butter mixture on top. Pour the remaining brownie batter over the top, then use a knife or skewer to swirl the peanut butter into the batter in a marbled pattern. Take your time for a beautiful, even swirl—don’t overmix.

Step 6

Bake: Place the pan in the preheated oven and bake for 30–35 minutes. Check doneness by inserting a toothpick in the center; it should come out with a few moist crumbs but not wet batter.

Step 7

Cool completely: Remove the pan from the oven and allow the brownies to cool in the pan for at least 20 minutes. Then lift them out using the parchment overhang and place on a wire rack to cool completely. Cooling fully allows the swirl to set and makes slicing cleaner.

Step 8

Serve: Cut into squares and arrange on a serving platter. These brownies are perfect for dessert tables, afternoon treats, or paired with a cold glass of milk. For extra flair, drizzle a little melted peanut butter or sprinkle chocolate chips on top before serving.

Tips for Perfect Peanut Butter Swirl Brownies

• Use unsalted butter to control sweetness; it makes the chocolate flavor pop.
• Don’t overmix the batter; folding gently keeps the brownies fudgy and tender.
• Melt butter over low heat and let it cool slightly before adding eggs.
• Swirl peanut butter using a knife in slow, circular motions for a pretty pattern.
• Bake until a toothpick comes out with moist crumbs, not wet batter.
• Let brownies cool completely in the pan before cutting for clean squares.
• Store in an airtight container to keep the texture soft and chocolatey for days.

Optional Ingredients

• Chopped peanuts for extra crunch
• Chocolate chips for more chocolate flavor
• Caramel drizzle for sweetness
• Sea salt flakes on top for a salty-sweet balance
• Espresso powder to enhance chocolate flavor
• Mini peanut butter cups to mix inside the batter

How to Serve Peanut Butter Swirl Brownies?

I like to serve these brownies warm straight from the pan when possible. The chocolate is soft, and the peanut butter swirl is slightly melty, which makes every bite indulgent and creamy. I often cut them into bite-sized squares for parties or afternoon snacks—small pieces are perfect for sharing without feeling guilty.

I also love pairing them with a scoop of ice cream. Vanilla, chocolate, or even coffee-flavored ice cream complements the rich chocolate and peanut butter flavors beautifully. A drizzle of chocolate or caramel sauce on top makes it feel like a fancy café dessert without any fuss. It’s amazing how such simple additions can make these brownies feel special and festive.

Sometimes, I serve them on a beautiful platter with a few extra touches. Sprinkling crushed peanuts, a light dusting of powdered sugar, or even a few mini chocolate chips makes the brownies look extra inviting. Whether it’s for friends, family, or just a cozy night in, this presentation adds a little wow factor without much effort.

Is Peanut Butter Swirl Brownies Healthy?

While these brownies are rich and indulgent, they do have some nutritional benefits. Peanut butter adds protein and healthy fats, while cocoa powder contains antioxidants. That said, they are still a dessert with sugar and butter, so it’s best to enjoy them in moderation.

If you make a smaller portion or pair the brownies with fruit, you can enjoy them as a balanced treat. They are definitely more of a comfort food than a health food, but the peanut butter gives a slight nutritional boost that makes them feel slightly less guilty.

Variations and Substitutions

• Gluten-Free: Use almond flour or a gluten-free flour blend. The brownies will be a little denser but still fudgy.
• Vegan: Replace butter with coconut oil and use flax eggs. The peanut butter flavor remains just as rich.
• Dark Chocolate: Swap cocoa powder for dark chocolate or use bittersweet chocolate chips. Adds a deeper chocolate flavor.
• White Chocolate Swirl: Replace peanut butter with melted white chocolate for a sweeter, creamy twist.
• Nut-Free: Use sunflower seed butter instead of peanut butter. Perfect for allergy-friendly brownies.
• Mocha Brownies: Add a teaspoon of instant coffee to the batter to enhance chocolate flavor and add depth.
• Chunky Peanut Butter: Use crunchy peanut butter for extra texture in every bite.
• Salted Caramel: Drizzle caramel sauce over the peanut butter swirl before baking for a decadent version.

How to Store, How to Reheat

To store your brownies, wrap them tightly in plastic wrap or place in an airtight container. They can last at room temperature for up to 4 days, or in the fridge for up to a week. If you want longer storage, they freeze beautifully for up to 3 months. Make sure to separate layers with parchment paper to avoid sticking.

To reheat, place a square in the microwave for 10–15 seconds to bring back the soft, gooey texture. You can also warm them in the oven at 300°F (150°C) for 5–7 minutes. Serving warm enhances the peanut butter swirl and gives a fresh-baked taste even a few days later.

Frequently Asked Questions About Peanut Butter Swirl Brownies

Can I use crunchy peanut butter?
Yes! Crunchy peanut butter adds a nice texture, giving each bite a little extra crunch. Swirl it gently so the marbled effect still looks pretty, and don’t worry if a few little chunks stick out—they add character.

Can I make these brownies in a larger or smaller pan?
Absolutely. For a larger pan, the brownies will be thinner, so bake a few minutes less; for a smaller pan, they’ll be thicker, so check for doneness and add a few extra minutes if needed. Adjusting the baking time ensures fudgy, evenly cooked brownies.

Do I have to use powdered sugar in the peanut butter swirl?
No, it’s optional. Powdered sugar helps the peanut butter blend more easily and makes the swirl sweeter. If you skip it, your swirl will still taste delicious but slightly less sweet and more nutty.

Can I double or triple this recipe?
Yes! Just scale the ingredients proportionally and use a larger pan. Baking time may change slightly depending on thickness, so keep an eye on the brownies and test with a toothpick for doneness.

Peanut Butter Swirl Brownies Recipe

Recipe by Maria MeyerCourse: Dessert / SnackCuisine: AmericanDifficulty: Medium

Servings

12

servings

Prep time

15

minutes

Cooking time

35

minutes

Calories

300

kcal

Indulge in rich and fudgy Peanut Butter Swirl Brownies! Easy to make, full of chocolate and creamy peanut butter, perfect for snacks, parties, or cozy treats.

Ingredients

• 1/2 cup (115g) unsalted butter

• 1 cup (200g) granulated sugar

• 2 large eggs

• 1 teaspoon vanilla extract

• 1/3 cup (40g) unsweetened cocoa powder

• 1/2 cup (65g) all-purpose flour

• 1/4 teaspoon salt

• 1/4 teaspoon baking powder

• 1/3 cup (80g) creamy peanut butter

• 2 tablespoons powdered sugar (optional, for easier swirling)

Directions

• Prepare the pan: Preheat your oven to 350°F (175°C). Line an 8×8-inch (20×20 cm) baking pan with parchment paper, leaving a little overhang for easy removal. This ensures the brownies won’t stick and makes slicing easier later.
• Melt the butter: In a small saucepan over low heat, melt the butter completely. Remove from heat and let it cool slightly. This will help the batter mix smoothly without cooking the eggs when added.
• Mix the brownie batter: In a medium bowl, whisk together the sugar and eggs until light and slightly fluffy. Add vanilla extract and the melted butter, stirring until fully incorporated. Gradually sift in cocoa powder, flour, salt, and baking powder. Fold gently until the mixture is smooth and thick. Avoid overmixing to keep the brownies tender.
• Prepare the peanut butter swirl: In a small bowl, mix the peanut butter with powdered sugar (if using) until smooth and slightly thinner in consistency. This helps the swirl spread more easily throughout the batter.
• Layer and swirl: Pour half of the brownie batter into the prepared pan and smooth it evenly. Drop spoonfuls of the peanut butter mixture on top. Pour the remaining brownie batter over the top, then use a knife or skewer to swirl the peanut butter into the batter in a marbled pattern. Take your time for a beautiful, even swirl—don’t overmix.
• Bake: Place the pan in the preheated oven and bake for 30–35 minutes. Check doneness by inserting a toothpick in the center; it should come out with a few moist crumbs but not wet batter.
• Cool completely: Remove the pan from the oven and allow the brownies to cool in the pan for at least 20 minutes. Then lift them out using the parchment overhang and place on a wire rack to cool completely. Cooling fully allows the swirl to set and makes slicing cleaner.
• Serve: Cut into squares and arrange on a serving platter. These brownies are perfect for dessert tables, afternoon treats, or paired with a cold glass of milk. For extra flair, drizzle a little melted peanut butter or sprinkle chocolate chips on top before serving.