This recipe is my go-to for celebrations, potlucks, and any day that demands chocolate therapy. I first discovered this layered treat on a sleepy weekend when I wanted something that felt indulgent but was simple enough to make without a stand mixer. The result was a thick, almost brownie-cake hybrid that stayed gooey in the center and offered a salty-sweet peanut butter surprise in every bite. It quickly became the dessert everyone requested at family gatherings and helped me win over even the most staunch chocolate purists.

The texture is the star: dense, fudgy brownie with chewy edges and a ribbon of creamy peanut butter that cuts through the chocolate richness. A silky bittersweet ganache on top seals the experience, adding shine and a concentrate of chocolate flavor. These bars are flourless by design, naturally gluten-free, and they hold their shape beautifully thanks to cornstarch—no special equipment required beyond basics you already own.

Ingredients

• Peanut Butter Filling: Use smooth, well-stirred peanut butter for a silkier filling—look for natural brands without excess oil separation, or stir thoroughly before measuring. The sugar and egg create a slightly set but still creamy ribbon when baked.
• Chocolate: Choose good quality semi-sweet or bittersweet chocolate chips or chopped bars (12 ounces). Brands like Ghirardelli or Guittard give predictable melt and deep chocolate flavor; bittersweet works best if you prefer less sweetness.
• Butter: Unsalted butter helps control sodium—6 tablespoons cut into small cubes melts faster and produces a glossy texture when combined with chocolate.
• Sugar & Vanilla: Granulated sugar balances bitterness and helps set the batter. Pure vanilla extract rounds flavor—1 teaspoon is sufficient to lift the chocolate notes.
• Eggs: Use room temperature eggs for smoother incorporation and improved volume when beaten into the melted chocolate mixture.
• Cocoa powder, Cornstarch & Salt: Unsweetened cocoa powder adds chocolate intensity; cornstarch replaces flour in this recipe to give structure while keeping the interior fudgy. A half teaspoon of salt balances sweetness and highlights flavors.
• Mini Chocolate Chips: One cup adds pockets of melty chocolate inside the batter; use mini chips so they disperse evenly.
• Ganache: Bittersweet chocolate and heavy cream create a glossy finish—10 ounces chopped chocolate with a half cup of cream yields a pourable ganache that sets firm in the fridge.

Instructions

Step 1 — Prepare the Pan:Preheat the oven to 350F. Lightly spray a 9-inch square baking pan and line it with parchment paper leaving an overhang for easy removal. This step prevents sticking and gives you clean edges when you lift the slab out to slice.Step 2 — Make the Peanut Butter Layer:In a medium bowl, whisk together 3/4 cup peanut butter, 1/2 cup granulated sugar, and 1 room temperature egg until smooth. The sugar helps stabilize the filling while baking, creating a cohesive ribbon that holds its shape when layered.Step 3 — Melt Chocolate and Butter:Place 12 ounces semi-sweet or bittersweet chocolate chips and 6 tablespoons butter in a large microwave-safe bowl. Heat in 30-second intervals on high, stirring between each interval until fully melted and glossy. Avoid overheating to prevent graininess—stirring distributes residual heat and finishes melting.Step 4 — Build the Batter:Stir in 3/4 cup granulated sugar and 1 teaspoon vanilla until combined. Add eggs one at a time, stirring thoroughly after each to incorporate. In a small bowl, whisk together 1/4 cup unsweetened cocoa powder, 1/3 cup cornstarch, and 1/2 teaspoon salt; then add to the chocolate mixture and stir vigorously until the batter is smooth and pulls away from the bowl sides—this can take one to two minutes of stirring.Step 5 — Add Mix-ins and Layer:Fold in 1 cup mini semi-sweet chocolate chips. Pour two-thirds of the batter into the prepared pan and smooth the top. Drop small spoonfuls of the peanut butter mixture across the batter. Spoon the remaining batter on top and smooth lightly with the back of a spoon or offset spatula—you want visible swirls, not perfect coverage.Step 6 — Bake and Cool:Bake 33 to 37 minutes or until a toothpick inserted into the center comes out with a few moist crumbs. Watch closely after 30 minutes—the pull-from-oven window is small. Cool completely on a rack; chilling speeds ganache application and yields cleaner slices.Step 7 — Make the Ganache:Place 10 ounces chopped bittersweet chocolate in a heatproof bowl. Heat 1/2 cup heavy whipping cream until scalding and pour over the chocolate. Let sit 5 minutes, then stir until smooth. If needed, microwave briefly in 15-second bursts, stirring until silky.Step 8 — Finish and Serve:Pour ganache over cooled brownies and spread evenly with an offset spatula. Refrigerate until the ganache sets. Use the parchment overhang to lift the slab out and cut into 36 small bars. Store in the fridge in an airtight container.

Storage Tips

Store the bars in an airtight container in the refrigerator for up to 3 days for the best texture and sheen on the ganache. For longer storage, individually wrap cooled squares in plastic wrap and place in a freezer-safe container or bag for up to 3 months. Thaw overnight in the refrigerator and bring to room temperature briefly before serving to allow the chocolate to soften. Avoid storing at room temperature for extended periods, as the ganache can become too soft and the peanut butter layer may lose its neat ribbon texture.

Ingredient Substitutions

If you prefer a nuttier profile, use crunchy peanut butter in the filling for texture—expect slightly more spread. Swap peanut butter for almond butter for a different flavor; reduce the added sugar by 1 tablespoon if the nut butter is sweetened. For a dairy-free version, substitute dairy-free chocolate and use a coconut cream ganache made from full-fat canned coconut milk—note the flavor shifts toward coconut and the ganache may be slightly less glossy.

Serving Suggestions

Serve warm with a small scoop of vanilla ice cream or chilled with a dollop of whipped cream to balance the richness. Garnish with a light sprinkle of flaky sea salt or crushed toasted peanuts for crunch and contrast. These bars are perfect for dessert platters, holiday trays, or boxed gifts; cut small and arrange on parchment-lined trays with a decorative ribbon for a polished presentation.

Cultural Background

While brownies are an American classic, the peanut butter pairing taps into a long tradition of combining chocolate with roasted nuts and nut butters in U.S. baking. Layered bars like these echo the retro appeal of multi-component desserts—think peanut butter cups or layered candy bars—updated with a modern, flourless base. Regional variations can include swapping peanut butter for local nut pastes or adding coffee to the chocolate for deeper, mocha notes.

Seasonal Adaptations

In cooler months, amplify warmth by stirring 1/2 teaspoon instant espresso granules into the melted chocolate for a cozy deep flavor. For summer gatherings, cut bars smaller and serve chilled with a bright berry compote to cut the richness. Around the holidays, fold 1/4 teaspoon cinnamon into the batter or top the ganache with crushed peppermint for a festive twist.

Meal Prep Tips

These bars are ideal for batch prep: bake a pan, chill, and portion into single-serve containers for office lunches or dessert grab-and-go. Refrigerated bars keep well for several days; freeze extras to maintain freshness. Label containers with the date and rotate older batches to the front of the fridge or freezer to ensure nothing goes to waste. Bring frozen bars to the fridge the night before to thaw gently.

These brownies have become my signature potluck contribution because they travel well and impress a crowd. Try them once and you’ll see why family and friends keep asking for the recipe—then make an extra batch to stash away for emergencies.