Fudgy Peanut Butter Swirl Brownies
If you’re on the hunt for a dessert that delivers on both texture and flavor, look no further than these Fudgy Peanut Butter Swirl Brownies! These decadent brownies are rich, chocolatey, and swirled with creamy peanut butter, making them the perfect treat for chocolate and peanut butter lovers alike. Each bite is a harmonious blend of fudgy goodness and nutty delight that will have you reaching for seconds (and maybe even thirds). Let’s dive into the reasons why these brownies deserve a spot in your recipe repertoire!
Top Reasons to Make Fudgy Peanut Butter Swirl Brownies

- Irresistible Flavor: The combination of rich chocolate and creamy peanut butter is a match made in dessert heaven.
- Easy to Make: With simple ingredients and straightforward steps, these brownies come together quickly, perfect for any novice or experienced baker.
- Perfect Texture: These brownies are fudgy, chewy, and melt-in-your-mouth delicious, offering the ideal brownie experience.
- Great for Sharing: Whether it’s a family gathering, a potluck, or just a cozy night in, these brownies are sure to impress and satisfy a crowd.
What We’re Using
To create the ultimate Fudgy Peanut Butter Swirl Brownies, gather the following ingredients:
- 4 ounces (113g) unsweetened baking chocolate, coarsely chopped: This is the base of our rich brownie batter.
- 1 cup (170g) unsalted butter: Adds moisture and richness to the brownies.
- 1 1/2 cups (300g) granulated sugar: Sweetens the brownies and helps achieve that perfect fudgy texture.
- 1 teaspoon salt: Enhances the flavors and balances the sweetness.
- 3 large eggs: Provides structure and richness to the batter.
- 1 teaspoon vanilla extract: Adds a warm, aromatic flavor.
- 2 tablespoons (10g) Dutch-process cocoa powder: Deepens the chocolate flavor; regular unsweetened cocoa can be used as a substitute.
- 1 cup (124g) all-purpose flour: Gives the brownies their structure.
- 1/2 cup (133g) peanut butter: The star of the show in our peanut butter swirl!
- 2 tablespoons (28g) unsalted butter, melted: Helps to combine the peanut butter for easy swirling.
- 1/2 cup (38g) powdered sugar: Sweetens the peanut butter layer and gives it a creamy texture.
- 1 teaspoon vanilla: For an extra boost of flavor in the peanut butter swirl.
Recommended Tools
To make the process smooth and enjoyable, gather these essential tools:
- Mixing bowls: A set of various sizes for mixing the brownie batter and peanut butter swirl.
- Whisk or electric mixer: For efficiently incorporating the ingredients.
- 9×9-inch baking pan: The perfect size for achieving a thick, fudgy brownie.
- Parchment paper: For easy removal of brownies from the pan and minimal cleanup.
- Rubber spatula: Ideal for scraping down the sides of the bowl and mixing the batters.
Fudgy Peanut Butter Swirl Brownies in Steps

Step 1: Preheat Your Oven
Start by preheating your oven to 350°F (175°C). This ensures that your brownies bake evenly and come out perfectly fudgy.
Step 2: Prepare the Baking Pan
Line your 9×9-inch baking pan with parchment paper, allowing some overhang for easy lifting later. This will make cutting the brownies much easier!
Step 3: Melt Chocolate and Butter
In a medium saucepan over low heat, combine the coarsely chopped unsweetened baking chocolate and 1 cup of unsalted butter. Stir frequently until melted and smooth. Remove from heat and allow to cool slightly.
Step 4: Mix in Sugar and Eggs
In a large mixing bowl, whisk together the granulated sugar and salt. Add the melted chocolate mixture and stir until well combined. Then, add the eggs, one at a time, mixing well after each addition. Finally, stir in the vanilla extract.
Step 5: Incorporate Dry Ingredients
Sift the Dutch-process cocoa powder and all-purpose flour into the bowl with the wet ingredients. Gently fold the dry ingredients into the batter using a rubber spatula until just combined. Be careful not to overmix!
Step 6: Prepare the Peanut Butter Swirl
In a separate bowl, mix together the peanut butter, melted butter, powdered sugar, and 1 teaspoon of vanilla extract until smooth and creamy.
Step 7: Layer the Batters
Pour half of the brownie batter into the prepared baking pan, smoothing it into an even layer. Dollop spoonfuls of the peanut butter mixture on top. Use a knife or a skewer to gently swirl the peanut butter into the brownie batter. Then, pour the remaining brownie batter on top and again swirl with the remaining peanut butter mixture.
Step 8: Bake
Place the pan in the preheated oven and bake for 25-30 minutes, or until a toothpick inserted in the center comes out with a few moist crumbs. Be careful not to overbake, as you want that fudgy texture!
Step 9: Cool and Slice
Once baked, remove the brownies from the oven and let them cool in the pan for about 15 minutes. Then, use the parchment overhang to lift them out onto a wire rack to cool completely before slicing into squares.
Smart Substitutions

If you’re looking to make adjustments, consider these substitutions:
- Butter: You can use a vegan butter alternative for a dairy-free version.
- Granulated Sugar: Coconut sugar or a sugar substitute can be used for a healthier option.
- Peanut Butter: Almond butter or cashew butter will work if you prefer a different nutty flavor.
- All-purpose Flour: Gluten-free all-purpose flour can be used to make these brownies gluten-free.
What Could Go Wrong
Even the best bakers can encounter a few hiccups. Here’s what to watch for:
- Overmixing: Mixing too vigorously after adding the flour can lead to tough brownies.
- Overbaking: Keep an eye on the baking time; brownies should be fudgy, not dry.
- Uneven Swirls: Don’t over-swirl the peanut butter mixture; you want to see distinct swirls, not a complete mix.
- Burnt Edges: If your oven runs hot, consider using an oven thermometer to ensure accurate temperature.
Keep It Fresh: Storage Guide
To keep your Fudgy Peanut Butter Swirl Brownies fresh:
- At Room Temperature: Store in an airtight container for up to 4 days.
- In the Refrigerator: They can last for up to a week when stored properly.
- For Longer Storage: Freeze cut brownies in an airtight container or freezer bag for up to 3 months. Thaw at room temperature before enjoying.
Questions People Ask
Can I use milk chocolate instead of unsweetened chocolate?
While you can use milk chocolate, be aware that it will make the brownies sweeter and alter the texture slightly. Adjust the sugar accordingly to avoid overly sweet brownies.
How do I know when my brownies are done?
The best way to check for doneness is to insert a toothpick into the center. If it comes out with a few moist crumbs, your brownies are ready. If it comes out wet, give them a few more minutes.
Can I make these brownies ahead of time?
Absolutely! These brownies keep well, so you can bake them a day or two in advance. Just store them properly to maintain freshness.
What’s the best way to cut brownies?
For clean cuts, use a sharp knife and wipe it clean between cuts. This prevents the edges from getting messy and helps maintain the beautiful swirls.
Final Thoughts
These Fudgy Peanut Butter Swirl Brownies are not just a treat; they are an experience. The rich chocolate base paired with the creamy peanut butter creates a delightful contrast that is hard to resist. Whether you’re enjoying them with a cup of coffee, serving them at a gathering, or indulging in a late-night snack, these brownies are sure to satisfy your sweet tooth.
So, roll up your sleeves, gather your ingredients, and treat yourself to a batch of these scrumptious brownies today. You deserve it!

Fudgy Peanut Butter Swirl Brownies
Ingredients
Equipment
Method
- Preheat your oven to 350°F (175°C).
- Line your 9x9-inch baking pan with parchment paper.
- In a medium saucepan over low heat, combine the baking chocolate and unsalted butter. Stir until melted and smooth.
- In a large mixing bowl, whisk together sugar and salt. Add the melted chocolate mixture, then add eggs one at a time, mixing well after each.
- Sift cocoa powder and flour into the wet ingredients. Fold gently until just combined.
- In a separate bowl, mix peanut butter, melted butter, powdered sugar, and vanilla until smooth.
- Pour half of the brownie batter into the pan, dollop peanut butter mixture on top, and swirl. Pour remaining brownie batter and swirl with remaining peanut butter.
- Bake for 25-30 minutes, until a toothpick comes out with moist crumbs.
- Cool in the pan for 15 minutes, then lift out and cool completely before slicing.
Notes
- Store brownies in an airtight container at room temperature for up to 4 days.
- For longer storage, freeze in an airtight container for up to 3 months.
- Use a sharp knife for clean cuts between slices.
