Fudgy Peanut Butter Brownies are the perfect fusion of two beloved classics: rich, chocolatey brownies and smooth, creamy peanut butter. These indulgent squares offer an intense chocolate flavor with a soft, chewy texture and decadent swirls of peanut butter that add just the right balance of sweet and salty. Whether served as a dessert, a lunchbox treat, or a bake sale favorite, they’re guaranteed to satisfy any craving for something deeply chocolaty with a nutty twist. Loved by both kids and adults, these brownies are simple to make yet feel luxurious, making them the perfect go-to for casual snacks, special occasions, or any moment you need a little extra comfort on your plate.
The History of Fudgy Peanut Butter Brownies
Brownies originated in the United States in the late 19th century and quickly became a staple of American baking culture. The earliest known published brownie recipes appeared in the early 1900s, and over time, countless variations emerged, including cakey, chewy, and fudgy types. Fudgy brownies, in particular, became popular for their dense texture and rich, chocolate-forward flavor that feels almost like biting into a piece of candy. The pairing of chocolate and peanut butter gained massive popularity in the mid-20th century, thanks in part to candy innovations like Reese’s. It was only a matter of time before creative bakers started swirling peanut butter into brownie batter, creating a combination that brought together the deep richness of chocolate with the nutty, slightly salty creaminess of peanut butter. Today, Fudgy Peanut Butter Brownies are beloved across the world as a delightful hybrid dessert that captures the best of both flavors.
Ingredients Breakdown
- Butter: Provides fat for richness and contributes to the dense, fudgy texture of the brownies.
- Granulated sugar: Sweetens the batter and helps give the brownies a crackly top.
- Brown sugar (optional): Adds moisture and a subtle molasses flavor, enhancing the chewiness.
- Eggs: Bind the ingredients and add structure while also contributing to the fudgy texture.
- Vanilla extract: Enhances the chocolate and peanut butter flavors.
- Unsweetened cocoa powder: Provides the deep chocolate flavor—Dutch-processed or natural cocoa both work.
- All-purpose flour: The main dry ingredient, providing structure to the brownies without making them too cakey.
- Salt: Balances the sweetness and enhances the overall flavor.
- Peanut butter: Swirled into the batter or dolloped on top, it adds richness, creaminess, and a salty contrast to the chocolate. Creamy peanut butter works best, but crunchy can be used for texture.
Step-by-Step Recipe
- Preheat your oven to 350°F (175°C) and line an 8×8-inch (20×20 cm) baking pan with parchment paper, leaving some overhang on the sides for easy removal.
- Melt the butter in a microwave-safe bowl or over low heat on the stove. Stir in the granulated sugar (and brown sugar, if using) while the butter is still warm until the mixture is smooth and glossy.
- Add the eggs and vanilla to the sugar-butter mixture and beat well until fully combined and slightly thickened.
- Sift in the cocoa powder, flour, and salt, then stir just until no dry streaks remain—do not overmix.
- Pour the batter into the prepared pan and smooth the top with a spatula.
- Dollop spoonfuls of peanut butter over the top of the brownie batter, then use a butter knife or toothpick to swirl it into decorative patterns.
- Bake for 25–30 minutes, or until a toothpick inserted in the center comes out with moist crumbs but no raw batter.
- Let the brownies cool completely in the pan before lifting them out and slicing. Cooling allows the fudgy texture to set fully.
- Serve and enjoy on their own or with a scoop of vanilla ice cream for extra indulgence.
Tips for the Perfect Fudgy Brownies
Use room temperature eggs—they incorporate better into the batter and help achieve a consistent texture. Don’t overbake the brownies; the center should still look slightly underdone when you take them out to preserve that rich, gooey interior. For a deeper chocolate flavor, use high-quality cocoa powder. Swirl the peanut butter gently so you get visible ribbons in each bite instead of mixing it fully into the batter. If your peanut butter is too thick to swirl easily, microwave it for 15–20 seconds to loosen it up. Let the brownies cool before cutting—cutting too early can cause them to fall apart. Use a plastic knife or one cleaned between each cut for perfect edges.
Variations and Customizations
Swap the peanut butter with almond butter, hazelnut spread, or sunflower seed butter for different flavor profiles. Add chocolate chips, chopped nuts, or Reese’s pieces to the batter for extra texture. Mix a pinch of espresso powder into the batter to intensify the chocolate flavor. For a gluten-free version, use a 1:1 gluten-free baking flour blend. Make them extra decadent by layering in a peanut butter filling or topping them with a peanut butter ganache. Add a pinch of cinnamon or a splash of bourbon to elevate the richness. For a salted twist, sprinkle flaky sea salt on top just before baking.
Health Considerations and Nutritional Value
Fudgy Peanut Butter Brownies are a delicious indulgence and should be enjoyed in moderation. On average, each brownie square contains approximately 200–300 calories, depending on the ingredients and size. They are rich in fats due to the butter and peanut butter and also contain sugars, which give them their sweet flavor and soft texture. To make a lighter version, you can reduce the sugar slightly or replace part of the butter with unsweetened applesauce. Natural peanut butter without added sugar or oils can also be used to cut back on processed ingredients. Though not low in calories, these brownies do provide a bit of protein from the peanut butter and eggs, along with some dietary fiber from cocoa powder. If dietary restrictions are a concern, they can be made gluten-free, dairy-free, or vegan with appropriate substitutions like flax eggs, dairy-free butter, and plant-based chocolate.
FAQ
Can I use natural peanut butter? Yes, but make sure it’s well stirred and not too runny. Some separation is normal, but overly oily peanut butter can affect the texture.
Can I make them without peanut butter? Absolutely—just leave out the peanut butter or replace it with another spread like Nutella or cookie butter.
How do I store them? Store in an airtight container at room temperature for up to 4 days or in the fridge for up to a week. You can also freeze them for up to 3 months.
Can I double the recipe? Yes—just bake in a 9×13-inch pan and adjust the baking time to around 35–40 minutes.
Can I make them vegan? Yes—use flax eggs (1 tablespoon flaxseed meal + 3 tablespoons water per egg), plant-based butter, and ensure your cocoa powder is vegan.
Can I use oil instead of butter? You can, but it will slightly change the flavor and texture. Butter provides a richer taste and better structure.
How do I get clean brownie slices? Let them cool completely, then use a sharp knife wiped clean between each cut. Refrigerating them before slicing can also help.
What kind of cocoa powder works best? Unsweetened Dutch-process cocoa powder gives a smoother, darker chocolate flavor, but natural cocoa powder works just fine.
Fudgy Peanut Butter Brownies
Ingredients
For the brownie base:
- ¾ cup 4.5 oz semi-sweet chocolate, coarsely chopped
- ¾ cup unsalted butter
- ¾ cup granulated sugar
- ¾ cup dark brown sugar
- 3 eggs at room temperature
- 2 teaspoons vanilla extract
- A few drops of almond extract
- 1 cup all-purpose flour
- 1½ tablespoons unsweetened cocoa powder
For the peanut butter swirl:
- ⅔ cup peanut butter
- 5 tablespoons powdered sugar
- ½ teaspoon vanilla extract optional
- 2 to 3 tablespoons cream double, whipping, or heavy cream
Instructions
For the brownie base:
- Preheat the oven to 350ºF (180ºC).
- Grease or spray an 8-inch square metal baking pan (avoid using glass), and line the bottom and two sides with parchment paper, leaving the remaining two sides unlined for easy lifting.
- In a large microwave-safe bowl, melt the chocolate and butter together, stirring every 10 seconds until the mixture is smooth. Alternatively, melt them over a pot of simmering water, making sure the bottom of the bowl doesn’t touch the water, and stir until fully melted.
- Stir in the granulated and brown sugars until well blended.
- Add the eggs, vanilla extract, almond extract (if using), and cocoa powder. Mix until fully combined.
- Gradually add the flour in two additions, mixing gently each time—avoid overmixing.
- Pour and spread the brownie batter evenly into the prepared pan.
For the peanut butter swirl:
- In a medium bowl, combine the peanut butter, powdered sugar, vanilla (if using), and cream. Stir until the mixture is smooth and no lumps remain.
- Drop spoonfuls of the peanut butter mixture over the brownie batter. Use a knife to gently swirl it into the batter, making sure to leave some large streaks or chunks intact to maintain the marbled effect.
- Bake for 25 to 30 minutes, depending on your pan, until the top looks dry, the center is slightly jiggly, and a toothpick or cake tester inserted comes out with moist, fudgy crumbs. Do not overbake.
- Let the brownies cool completely on a wire rack.
- They taste even better the next day—wrap them in plastic and store at room temperature.
For longer storage, wrap them well and freeze.
Notes
For the peanut butter, I usually go with traditional commercial peanut butter, but natural peanut butter works just as well.
When creating the swirl, be gentle. You want the peanut butter mixture to remain distinct from the brownie batter, so don’t over-swirl—this helps maintain those beautiful ribbons and rich flavor contrast.
Pan size is key to achieving a perfectly fudgy, gooey texture that bakes evenly throughout.
When lining your pan, I highly recommend using just a single strip of parchment paper cut to the width of the pan. This will line only the bottom and two opposite sides. Avoid lining the whole pan with a square of paper that folds in the corners—since the brownie is very fudgy, it may stick to those folds.
When baking, aim to slightly underbake the brownies. The center should still have a jiggle when you take them out of the oven—this ensures that soft, gooey bite everyone loves.
For the best flavor and texture, wait until the next day to eat them. Letting them sit allows the brownies to fully develop in taste and structure. These brownies also freeze very well when wrapped tightly and can last at least a month in the freezer.
For an almond butter variation, substitute almond butter in the same amount as peanut butter. You can also replace the cocoa powder by grinding 2 tablespoons of cocoa nibs into a fine powder. For a different sweetness, try using coconut sugar instead of brown sugar. The rest of the recipe stays exactly the same.