Peanut Butter Stuffed Brownies

The moment I pulled my first batch of Peanut Butter Stuffed Brownies from the oven, I knew I had created something extraordinary. The intoxicating aroma of rich chocolate mingled with warm, nutty peanut butter filled my kitchen, making it nearly impossible to wait for them to cool before diving in. These Peanut Butter Stuffed Brownies combine two of life’s greatest culinary pleasures in perfect harmony—fudgy, chocolatey brownie encasing a molten layer of creamy peanut butter that creates a textural masterpiece. Each bite delivers the ideal balance: the slight crackle of the brownie top giving way to that fudgy chocolate center, then surprising your palate with the smooth, nutty peanut butter layer hidden within. Whether you’re baking for a special occasion or simply craving an indulgent treat, stay with me to discover how these Peanut Butter Stuffed Brownies will elevate your dessert game to legendary status.

Why You’ll Love These Peanut Butter Stuffed Brownies

If you’ve ever struggled with brownies that turn out too dry or bland, or if you’ve attempted stuffed desserts only to find the filling disappears during baking, these Peanut Butter Stuffed Brownies solve those common baking frustrations. The brownie base is practically foolproof, with a texture that remains perfectly fudgy while still holding its structure around the peanut butter center.

I first developed this recipe for my sister’s birthday—she’s always been torn between peanut butter cookies and chocolate brownies for her celebration dessert. The moment she bit into one of these brownies, her eyes widened, and she declared, “This is it. This is my birthday dessert forever.” Since then, these Peanut Butter Stuffed Brownies have become my most requested contribution to family gatherings, potlucks, and bake sales.

What makes these brownies truly special is their versatility. The basic recipe creates an irresistible dessert on its own, but it also serves as a perfect canvas for customization. You can easily adapt the recipe based on the occasion, your pantry inventory, or seasonal inspirations. Add holiday spices during winter months, incorporate fresh berries in summer, or experiment with different nut butters for variety.

Now, let’s explore exactly what you’ll need to create these magical Peanut Butter Stuffed Brownies in your own kitchen.

Ingredients for Perfect Peanut Butter Stuffed Brownies

For the Brownie Base:

  • 1 cup (226g) unsalted butter – Creates richness and moisture in your brownies. Use high-quality butter for better flavor. In a pinch, salted butter can work—just reduce the added salt by ¼ teaspoon.
  • 2 cups (400g) granulated sugar – Provides sweetness and contributes to that crackly top brownies are famous for. You can reduce to 1¾ cups if you prefer less sweet desserts.
  • 4 large eggs, room temperature – Acts as a binding agent and creates structure. Room temperature eggs incorporate better than cold ones. For a vegan option, try 4 flax eggs (4 tablespoons ground flaxseed mixed with 12 tablespoons water).
  • 1 tablespoon vanilla extract – Enhances all the other flavors. Pure vanilla extract offers the best flavor, but artificial works in a pinch.
  • 1 cup (85g) unsweetened cocoa powder – The foundation of chocolate flavor. Dutch-processed cocoa provides a smoother, less acidic taste, but natural cocoa powder works too.
  • 1 cup (125g) all-purpose flour – Provides structure. For gluten-free brownies, substitute a 1:1 gluten-free flour blend.
  • 1 teaspoon salt – Enhances the chocolate flavor and balances sweetness. I prefer kosher salt for baking.
  • 1 cup (175g) semi-sweet chocolate chips – Creates melty chocolate pockets throughout. Dark or milk chocolate chips work well too, depending on your preference.

For the Peanut Butter Filling:

  • 1 cup (260g) creamy peanut butter – The star of our filling. Natural peanut butter works but may create a slightly less stable filling due to its oils. For best results, use commercial brands like Jif or Skippy.
  • ¼ cup (50g) granulated sugar – Adds sweetness and helps stabilize the filling. Light brown sugar can be substituted for a deeper flavor.
  • ½ teaspoon vanilla extract – Enhances the peanut butter flavor. Almond extract makes an interesting variation.
  • ¼ teaspoon salt – Balances the sweetness and enhances the nutty flavor. Skip if using salted peanut butter.
  • 1 large egg – Helps the filling set properly. For egg allergies, 3 tablespoons of aquafaba (chickpea liquid) can work as a substitute.
  • 2 tablespoons all-purpose flour – Stabilizes the filling so it doesn’t completely melt into the brownie. Cornstarch can be used as an alternative.

Optional Finishing Touches:

  • ¼ cup chopped peanuts – For added texture and visual appeal. Can be omitted for those with nut allergies.
  • ¼ cup chocolate chips for topping – Creates an extra decadent appearance and flavor boost.
  • Flaky sea salt – A light sprinkle enhances all flavors and provides contrast to the sweetness.

How to Make Peanut Butter Stuffed Brownies

Step 1: Prepare Your Baking Equipment and Ingredients

  1. Preheat your oven to 350°F (175°C). Position the rack in the middle of the oven for even baking.
  2. Lightly grease a 9×13 inch baking pan, then line it with parchment paper, leaving an overhang on two sides to facilitate easy removal later. The parchment paper is crucial for clean removal of these gooey brownies.
  3. Gather all ingredients and allow refrigerated items like eggs and butter to come to room temperature. Room temperature ingredients incorporate more easily and create a better texture.

Step 2: Create the Peanut Butter Filling

  1. In a medium bowl, combine the creamy peanut butter, granulated sugar, vanilla extract, salt, egg, and flour. Mix until completely smooth and well incorporated. The mixture should be thick but still able to be spread.
  2. Cover the bowl with plastic wrap and refrigerate for at least 30 minutes. Chilling the filling makes it easier to handle and helps it maintain its distinct layer during baking.
  3. Once chilled, the filling should be firm enough to work with but still pliable—similar to a soft cookie dough consistency.

Step 3: Prepare the Brownie Batter

  1. In a large microwave-safe bowl or using a double boiler, melt the butter. If using a microwave, heat in 30-second intervals, stirring between each until fully melted.
  2. Add the granulated sugar to the melted butter and whisk vigorously for about 1 minute. This helps dissolve the sugar and contributes to that shiny, crackly top.
  3. Add the eggs one at a time, whisking well after each addition until fully incorporated. The mixture should become smooth and slightly lighter in color.
  4. Stir in the vanilla extract.
  5. Sift together the cocoa powder, flour, and salt, then gradually add to the wet ingredients, folding gently with a spatula until just combined. Do not overmix—this can lead to tough brownies.
  6. Fold in the chocolate chips, distributing them evenly throughout the batter.

Step 4: Assemble and Bake

  1. Pour about two-thirds of the brownie batter into the prepared pan, spreading it evenly with a spatula. The layer should be about ½ inch thick.
  2. Remove the peanut butter filling from the refrigerator. You have two options for adding the filling:
    • Option A: Using a tablespoon, drop dollops of the peanut butter mixture evenly across the surface of the brownie batter, then gently spread it into an even layer, leaving a ½-inch border around the edges.
    • Option B: For a more distinct layer, roll the peanut butter mixture between two sheets of parchment paper to roughly the size of your pan, then carefully transfer it onto the brownie layer.
  3. Carefully spread the remaining brownie batter over the peanut butter layer. Don’t worry if it doesn’t completely cover—some peanut butter peeking through creates a beautiful marbled effect.
  4. If using, sprinkle the top with additional chocolate chips and chopped peanuts.
  5. Bake for 30-35 minutes, until the edges are set and a toothpick inserted about 2 inches from the edge comes out with a few moist crumbs. The center may still seem slightly underdone—this is perfect for fudgy brownies.
  6. If you notice the top browning too quickly, tent loosely with aluminum foil for the last 10 minutes of baking.

Step 5: Cool and Serve

  1. Allow the brownies to cool completely in the pan on a wire rack, about 2-3 hours. This cooling period is crucial—cutting too soon will result in messy brownies.
  2. Once cooled, use the parchment paper overhang to lift the brownies out of the pan.
  3. For the cleanest cuts, chill the brownies in the refrigerator for about 30 minutes, then use a sharp knife dipped in hot water and wiped clean between cuts.
  4. If desired, sprinkle with flaky sea salt just before serving to enhance all the flavors.

Creative Variations on Peanut Butter Stuffed Brownies

Triple Chocolate Peanut Butter Brownies

Elevate the chocolate experience by using three types of chocolate. Add ¼ cup white chocolate chips and ¼ cup milk chocolate chips to the batter along with the semi-sweet chips. Drizzle the top with melted chocolate after baking for a stunning presentation. The varying sweetness levels of different chocolates create a complex flavor profile that chocolate connoisseurs will appreciate.

Salted Caramel Peanut Butter Brownies

Add a layer of salted caramel below or above the peanut butter filling. Either use ½ cup store-bought caramel sauce or make your own by melting ½ cup sugar with 2 tablespoons water until amber, then stirring in ¼ cup heavy cream, 2 tablespoons butter, and ½ teaspoon salt. The buttery caramel adds another dimension that perfectly complements both the chocolate and peanut butter.

Banana Peanut Butter Cup Brownies

Mix ½ cup mashed ripe banana into the brownie batter and substitute half the peanut butter with Nutella in the filling. Add ½ cup chopped peanut butter cups to the batter and sprinkle more on top before baking. The fruity banana notes balance the richness while nodding to the classic banana-peanut butter-chocolate combination.

Spiced Mexican Chocolate Peanut Butter Brownies

Add 1 teaspoon ground cinnamon, ¼ teaspoon cayenne pepper, and a pinch of nutmeg to the brownie batter. Use dark chocolate chips instead of semi-sweet, and add 1 tablespoon of coffee granules dissolved in 1 tablespoon hot water. The warm spices and coffee enhance the chocolate’s depth while creating an intriguing contrast with the creamy peanut butter layer.

Berry Peanut Butter Brownies

Add 1 cup fresh or frozen raspberries or strawberries to the brownie batter. For the filling, swirl 3 tablespoons of berry preserves into the peanut butter mixture. The tart berries cut through the richness and add beautiful color contrast. This variation is particularly wonderful during summer berry season.

Coconut Dream Peanut Butter Brownies

Add ½ cup toasted coconut flakes to the brownie batter and substitute coconut sugar for regular sugar. Mix 2 tablespoons coconut cream into the peanut butter filling, and sprinkle more toasted coconut on top before baking. The tropical notes of coconut create a vacation-worthy twist on the classic flavors.

Peanut Butter Stuffed Brownies

Peanut Butter Stuffed Brownies

These Peanut Butter Stuffed Brownies are pure chocolatey heaven! Fudgy brownies with a gooey peanut butter center—rich, decadent, and irresistible.
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Prep Time 15 minutes
Cook Time 35 minutes
Servings 12 Brownies
Calories 320 kcal

Equipment

  • ✔️ Mixing bowls

Ingredients
  

For the Brownie Base:

  • 1 cup 226g unsalted butter, melted
  • 2 cups 400g granulated sugar
  • 4 large eggs room temperature
  • 1 tbsp vanilla extract
  • 1 cup 85g unsweetened cocoa powder
  • 1 cup 125g all-purpose flour
  • 1 tsp salt
  • 1 cup 175g semi-sweet chocolate chips

For the Peanut Butter Filling:

  • 1 cup 260g creamy peanut butter
  • ¼ cup 50g granulated sugar
  • ½ tsp vanilla extract
  • ¼ tsp salt
  • 1 large egg
  • 2 tbsp all-purpose flour

Optional Toppings:

  • ¼ cup chopped peanuts
  • ¼ cup chocolate chips
  • Flaky sea salt

Instructions
 

1️⃣ Preheat Oven & Prep Pan

  • Preheat oven to 350°F (175°C).
  • Grease a 9×13 pan & line with parchment paper.

2️⃣ Make the Peanut Butter Filling

  • Mix peanut butter, sugar, vanilla, salt, egg & flour until smooth.
  • Chill for 30 minutes.

3️⃣ Make the Brownie Batter

  • Melt butter & whisk in sugar until smooth.
  • Add eggs one at a time, whisking after each.
  • Stir in vanilla.
  • Sift in cocoa powder, flour & salt; fold gently.
  • Stir in chocolate chips.

4️⃣ Assemble & Bake

  • Spread ⅔ of the brownie batter into the pan.
  • Evenly distribute peanut butter filling over the batter.
  • Spread remaining brownie batter on top.
  • Sprinkle optional toppings.
  • Bake for 30-35 min, until edges are set & center is fudgy.

5️⃣ Cool & Serve

  • Let brownies cool completely before cutting.
  • Chill for clean slices.
  • Enjoy!

Notes

  • Gluten-Free: Use a 1:1 gluten-free flour blend.
  • Vegan: Swap eggs for flax eggs (4 tbsp flaxseed + 12 tbsp water).
  • Spiced Version: Add 1 tsp cinnamon & ¼ tsp cayenne to brownie batter.
  • Salted Caramel Twist: Drizzle caramel over the peanut butter layer.

Nutrition

Serving: 1gCalories: 320kcalCarbohydrates: 38gProtein: 6gFat: 18gSugar: 24g
Keyword PeanutButterBrownies
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Frequently Asked Questions About Peanut Butter Stuffed Brownies

How do I store these brownies, and how long do they last?

These Peanut Butter Stuffed Brownies will stay fresh for up to 5 days when stored in an airtight container at room temperature. For maximum freshness, place a piece of bread in the container—the brownies will absorb moisture from the bread rather than drying out. For longer storage, refrigerate for up to a week, though the texture may become slightly more fudge-like. I actually prefer them slightly chilled, as the peanut butter layer becomes more distinct!

Can I freeze these brownies?

Absolutely! These brownies freeze beautifully for up to 3 months. Once completely cooled, cut into portions, then wrap individual brownies tightly in plastic wrap followed by aluminum foil or place in freezer-safe bags. To thaw, leave wrapped brownies at room temperature for about 2 hours. For a warm treat, microwave an unwrapped brownie for 15-20 seconds or heat in a 300°F oven for 5-7 minutes.

Why did my peanut butter layer melt into the brownie batter?

This typically happens if the peanut butter mixture isn’t properly chilled or stabilized. Make sure to refrigerate the filling for at least 30 minutes before assembling, and don’t skip the flour in the peanut butter mixture—it helps the filling maintain its integrity. Also, ensure your brownie batter has enough structure (don’t reduce the flour) to support the filling during baking.

Can I make these brownies with alternative nut butters?

Yes! Almond butter, cashew butter, or sunflower seed butter (for nut-free options) work wonderfully in this recipe. Keep in mind that different nut butters have varying oil contents and consistencies. If using a very runny nut butter, you might need to add an extra tablespoon of flour to the filling mixture to help it set properly.

My brownies are too gooey in the center. Did I underbake them?

Peanut Butter Stuffed Brownies are meant to be fudgy, especially around the filling. However, if they’re truly underbaked, the toothpick test 2 inches from the edge should help determine doneness—it should come out with a few moist crumbs, not wet batter. Remember that brownies continue cooking slightly as they cool. If you prefer a more set texture, add 3-5 minutes to the baking time, but watch carefully to avoid drying out the edges.

Can I make these brownies gluten-free or vegan?

For gluten-free brownies, substitute the all-purpose flour with a 1:1 gluten-free flour blend in both the brownie batter and peanut butter filling. For vegan brownies, use plant-based butter, flax eggs (1 tablespoon ground flaxseed mixed with 3 tablespoons water per egg), and ensure your chocolate chips are dairy-free. For the peanut butter filling, use a flax egg and confirm your peanut butter doesn’t contain honey. The texture may be slightly different, but still delicious!

A Sweet Connection Through Peanut Butter Stuffed Brownies

Last winter, I brought these Peanut Butter Stuffed Brownies to my grandfather’s 90th birthday celebration. He’s always been a man of simple tastes, preferring classic peanut butter sandwiches to fancy desserts. As conversations flowed around him in the crowded room, I noticed him quietly take a bite of my brownie. His eyes lit up, and he motioned me closer. “This,” he whispered with a smile, “is what happens when you respect tradition but aren’t afraid to improve it.”

That moment encapsulates what I love most about these Peanut Butter Stuffed Brownies. They honor the beloved classics—rich chocolate brownies and creamy peanut butter—while transforming them into something even more magical together. They remind us that sometimes the most meaningful innovations come not from reinventing the wheel, but from thoughtfully combining treasured favorites in new ways.

As you bake these brownies in your own kitchen, I encourage you to embrace both tradition and creativity. Start with this recipe as your foundation, but don’t be afraid to make adjustments that speak to your personal taste or incorporate family favorites. Perhaps you’ll add a special spice that reminds you of holidays at home, or swirl in a preserve made from berries you picked yourself. However you make them, these Peanut Butter Stuffed Brownies aren’t just a dessert—they’re an opportunity to create new memories around flavors that have brought joy for generations.