Double Decker Brownie Recipe

Preheat and prep pan

Preheat oven to 350°F (175°C). Line a 9x9-inch square baking pan with parchment paper, leaving a 1–2 inch overhang on opposite sides for easy removal. Lightly butter or spray the parchment.

Melt butter and base chocolate

Place the 0.75 cups (6 oz) chopped bittersweet chocolate and 0.75 cups butter in a heatproof bowl. Melt over a double boiler or in 20–30 second bursts in the microwave, stirring until smooth and fully combined. Allow to cool 3–5 minutes so it is warm but not hot.

Whisk sugars and eggs: In a large bowl, whisk together 1.25 cups granulated sugar and 0.25 cup light brown sugar. Add the 3 large eggs one at a time, whisking vigorously after each addition until fully incorporated and slightly thickened. Whisk in 2 tsp vanilla.

Combine chocolate and egg mixture: Slowly drizzle the melted chocolate–butter mixture into the egg mixture while whisking constantly to temper the eggs and create a glossy batter.

Sift dry ingredients and fold: Sift together 1 cup all-purpose flour, 0.25 cup unsweetened cocoa powder, 0.5 tsp kosher salt, and 0.5 tsp espresso powder (if using). Fold the dry mixture into the wet batter with a spatula just until no streaks remain. Do not overmix—batter should be thick and glossy.

Add nuts (optional): Fold in 0.75 cup chopped toasted nuts if using.

Pour two-thirds of the brownie batter into the prepared 9x9 pan and spread into an even layer using an offset spatula. Reserve the remaining batter for the top layer.

Bake the base layer for 18–20 minutes, until the edges are set and a toothpick inserted into the center comes out with moist crumbs but not raw batter. Remove from oven and let cool for 8–10 minutes while you prepare the Ghirardelli layer.

Heat cream: In a small saucepan, heat 0.5 cup heavy cream and 1 tsp light corn syrup until just simmering (do not boil).

Pour over chocolate: Place 8 oz Ghirardelli semisweet chips in a heatproof bowl. Pour the hot cream over the chips and let sit 1 minute, then stir gently until smooth and glossy. Stir in 1 tbsp room-temperature butter until incorporated for extra shine.

Cool slightly: Let the ganache cool 5–7 minutes so it thickens but is still pourable.

Spread over partially baked layer: Pour the ganache evenly over the warm but not hot brownie base, smoothing to the edges. The warmth of the brownie will help the ganache set a little.

Dollop and spread remaining batter: Drop spoonfuls of the reserved brownie batter over the ganache in an even pattern; using a small offset spatula swirl and gently spread to mostly cover the ganache leaving a marbled look if you prefer a double-decker appearance.

Bake again: Return the pan to the oven and bake for an additional 12–15 minutes, until the top is set but still fudgy inside. A toothpick inserted into the topmost layer should come out with moist crumbs from the ganache/brownie, not raw batter.

Cool: Remove from oven and allow to cool on a wire rack for at least 1 hour. The ganache will firm as it cools and the layers will set, but brownies will be very fudgy — for cleaner slices refrigerate for 1–2 hours or freeze 20–30 minutes before cutting.

Unmold and garnish: Use the parchment overhang to lift the brownie slab from the pan. Sprinkle 0.25 tsp coarse sea salt over the top while slightly warm if you like a salty contrast. Dust lightly with 1 tbsp powdered sugar if desired.

Slice and serve: Cut into 9 large or 16 smaller squares using a sharp knife warmed under hot water and wiped dry between cuts for cleaner edges. Store airtight at room temperature up to 3 days or refrigerated up to 5 days. For best gooey texture, bring to room temperature before serving.