This recipe started as a rescue mission. One rainy afternoon I had a craving for something intensely chocolatey and a jar of peanut butter staring back at me from the pantry. I wanted something rich, chewy, and utterly satisfying without the fuss of complicated equipment or obscure ingredients. The result was these flourless peanut butter brownies — an indulgent, fudgy bar with a ribbon of creamy peanut butter through the center and a shiny chocolate ganache on top. From the first bite, the contrast of dense chocolate and nutty sweetness felt like a tiny celebration in my mouth.

I first made these for a family gathering where the cookie table was already overflowing. Even so, these bars vanished faster than anything else. They travel well, cut cleanly when chilled, and the peanut butter layer makes every square feel like a carefully composed bite. They’re naturally gluten-free because there’s no flour, and you don’t need a mixer — just your hands for gentle stirring and a bit of patience while melting chocolate. Whether you’re bringing them to a potluck or making them for your own chocolate emergency, these brownies deliver decadent results with surprisingly little fuss.

Ingredients

• Peanut Butter Filling: 3/4 cup creamy peanut butter — choose a good-quality creamy brand for a smooth filling; natural styles can separate and alter texture, so stir well if using natural peanut butter.
• Granulated sugar: 1/2 cup — helps sweeten and stabilize the peanut butter layer so it sets cleanly when baked.
• Egg: 1 large, room temperature — room temperature eggs incorporate more evenly into the filling for consistent texture.
• Chocolate for the brownie: 12 oz semi-sweet or bittersweet chocolate chips — use 60–70% cacao for balanced bitterness and sweetness.
• Unsalted butter: 6 tablespoons, cut into small cubes — soften and melt evenly with the chocolate for glossy batter.
• Granulated sugar: 3/4 cup — adds sweetness and structure to the dense brownie.
• Vanilla extract: 1 teaspoon — lifts the chocolate flavors and balances the peanut butter.
• Eggs: 3 large, room temperature — beaten into the melted chocolate to create a thick, fudgy batter.
• Unsweetened cocoa powder: 1/4 cup — use dutch-process or natural; both work but will slightly change the flavor profile.
• Cornstarch: 1/3 cup — replaces flour to provide body and chew without gluten.
• Salt: 1/2 teaspoon — enhances the chocolate and balances sweetness.
• Mini semi-sweet chocolate chips: 1 cup — give pockets of melty chocolate throughout the bars.
• Ganache: 10 oz chopped bittersweet chocolate and 1/2 cup heavy whipping cream — heat the cream until scalding and pour over the chocolate for a smooth, glossy finish.

Instructions

Prepare the pan and preheat oven: Preheat the oven to 350°F. Lightly spray a 9-inch square baking pan and line it with parchment paper with an overhang; this makes removing and slicing the bars much easier once chilled. Set aside while you mix. Make the peanut butter filling: In a medium bowl combine 3/4 cup peanut butter, 1/2 cup granulated sugar, and 1 room-temperature egg. Stir until smooth and glossy — the sugar should be fully incorporated and the mixture slightly thick. Set aside at room temperature while you prepare the chocolate batter. Melt chocolate and butter: Place 12 oz chocolate chips and 6 tablespoons cubed butter in a large microwave-safe bowl. Microwave in 30-second bursts on high, stirring between each burst, until smooth and fully melted. Alternatively, melt gently over a double boiler, stirring until glossy. Combine sugar, vanilla, and eggs: Stir 3/4 cup sugar and 1 teaspoon vanilla into the melted chocolate until combined. Add the 3 eggs one at a time, stirring vigorously between additions so the mixture becomes thick, shiny, and slightly aerated. Add dry ingredients: Whisk together 1/4 cup cocoa powder, 1/3 cup cornstarch, and 1/2 teaspoon salt in a small bowl. Add the dry mix to the chocolate mixture and stir vigorously for one to two minutes until the batter smooths and begins to pull away from the sides of the bowl — this signals proper incorporation and a fudgy consistency. Fold in chips and assemble: Stir in 1 cup mini semi-sweet chocolate chips. Pour about two-thirds of the batter into the prepared pan and smooth an even layer. Drop spoonfuls of the peanut butter filling over the batter, spaced evenly. Spoon the remaining batter over the peanut butter blobs and smooth lightly with the back of a spoon or offset spatula — it doesn’t need to be perfect; swirls look lovely after baking. Bake and cool: Bake for 33–37 minutes. Start checking at 30 minutes; a toothpick inserted should come out with a few moist crumbs attached. Overbaking will dry them out, so err on the side of slightly underdone for the best fudgy texture. Cool completely on a rack or chill in the refrigerator to firm up before adding ganache.

Ganache and finishing

Make the ganache: Place 10 oz chopped bittersweet chocolate in a heat-proof bowl. Heat 1/2 cup heavy whipping cream until just scalding (do not boil) and pour over the chocolate. Let sit for 5 minutes, then stir until smooth. If needed, microwave in 15-second intervals, stirring between, until fully glossy. Top and set: Pour the ganache over the cooled brownies and smooth with an offset spatula. Refrigerate until the ganache is fully set, which usually takes 30–60 minutes. Use the parchment overhang to lift from the pan and slice into 36 bars.

Storage Tips

Store bars in an airtight container in the refrigerator to keep the ganache firm and the slices neat; they will keep well for up to 3 days. For longer storage, layer parchment between squares and freeze in a sealed container for up to 3 months. Thaw in the refrigerator overnight and bring to room temperature for 20–30 minutes before serving to soften the ganache slightly.

Ingredient Substitutions

If you don’t have mini chips, chop regular semi-sweet chips into small pieces. For a different nut profile, try almond butter in the filling but be aware it will change sweetness and texture slightly. Substitute coconut cream for heavy cream in the ganache for a dairy-free finish, but ganache texture and sheen may vary. If avoiding cornstarch, arrowroot can work one-to-one, though the texture will be marginally different.

Serving Suggestions

Serve these squares with a simple dusting of cocoa or flaky sea salt on top of the ganache for contrast. Pair with cold milk, strong coffee, or a lightly sweetened espresso for adult dessert plates. For a party, cut smaller two-bite pieces and arrange on a platter with fresh berries to balance the richness.

Cultural Background

Brownies are an American classic that emerged in the early 20th century. This version leans into the beloved peanut butter–chocolate pairing that has been popularized in American desserts and candies. The flourless approach borrows from dense, flourless chocolate confections and emphasizes ganache-like texture rather than cakey crumb.

Seasonal Adaptations

In colder months add a pinch of cinnamon or espresso powder to the batter to deepen flavor. For summer gatherings, top with chopped salted peanuts and serve slightly chilled. Holiday variations can include folding crushed peppermint into the ganache or swirling dulce de leche into the peanut butter layer for a caramel twist.

Meal Prep Tips

Make the bars a day ahead and let the ganache set overnight for silky slices. Store pre-cut squares in a single layer in an airtight container with parchment separators. If you need bite-sized servings for an event, halve each square and keep chilled until serving to maintain clean edges.

These brownies are a fail-safe crowd-pleaser: easy to make, indulgent to eat, and perfect for sharing. Try them once and you’ll understand why they’ve become a go-to for celebrations and cozy nights in. Enjoy the perfect marriage of fudgy chocolate, creamy peanut butter, and glossy ganache.