Chocolate Avalanche Recipe

Prepare and Preheat

Preheat oven to 350°F (175°C). Line a 9x9-inch square baking pan with parchment paper, leaving a 1-inch overhang to lift the baked brownie out easily; lightly butter the parchment.

Melt Chocolate and Butter

In a heatproof bowl set over (but not touching) simmering water or in short bursts in the microwave, melt 1 cup unsalted butter with 8 oz chopped bittersweet chocolate, stirring until smooth. Remove from heat and let cool 5 minutes.

Combine Wet Ingredients

Whisk 1.5 cups granulated sugar into the slightly cooled chocolate mixture until combined. Add 3 large eggs, one at a time, whisking well after each addition. Stir in 1 tsp vanilla extract.

Add Dry Ingredients

Sift together 1 cup all-purpose flour, 1/2 cup unsweetened cocoa powder, and 1/2 tsp fine sea salt. Fold the dry mixture into the chocolate batter gently until just combined; avoid over mixing.

Bake

Spread batter into the prepared 9x9 pan and smooth the top. Bake 20–25 minutes, until edges are set and a toothpick inserted near the center comes out with a few moist crumbs (do not overbake — center should remain fudgy). Remove from oven and allow to cool in pan on a wire rack for 10 minutes.

While the brownie is cooling, make the molten center: place 4 oz chopped bittersweet chocolate and 1/2 cup heavy cream in a small heatproof bowl. Microwave in 20-second intervals, stirring between, or heat cream until steaming and pour over chocolate. Let sit 1 minute, then whisk until smooth. Stir in 1 tablespoon unsalted butter until incorporated. Allow the molten center to cool slightly so it thickens but remains pourable (about 5–8 minutes).

Using the parchment overhang, lift the brownie slab from the pan and place on a cooling rack set over a sheet pan or plate. Using the back of a spoon, create a shallow well in the center of the warm brownie (press down gently about 1/2 inch deep), then pour the molten chocolate into the well, spreading to the edges of the depression. The warm brownie will take on a molten center; let set 10 minutes at room temperature.

Prepare the ganache: place 6 oz chopped chocolate in a medium bowl. In a small saucepan, bring 1 cup heavy cream just to a simmer (do not boil). Pour the hot cream over the chocolate and let sit 1–2 minutes, then whisk until smooth. Let ganache cool until thick but still pourable and slightly warm — about 20–30 minutes. Stir in confectioners' sugar (2 tbsp) to stabilize and sweeten; cool until it reaches spreading consistency.

For a lighter whipped topping: once the ganache has cooled and thickened, use an electric mixer to whip the ganache for 1–2 minutes on medium speed until fluffy and spreadable. If ganache is too firm, fold gently with a spatula to reach workable texture.

Spread or pipe the whipped chocolate ganache over the molten-topped brownie, leaving the very center slightly exposed if you want the molten center to peek through. Smooth the surface or create peaks for texture.

Scatter 1/2 cup toasted chopped hazelnuts or pecans evenly over the ganache. Dust lightly with 1 tablespoon cocoa powder and finish with 1/2 teaspoon flaky sea salt sprinkled across the top to heighten contrast.

Chill the assembled dessert in the refrigerator for 20–30 minutes to allow layers to firm slightly (but not become rock-hard) — this helps with clean slicing while maintaining a gooey center. Remove from fridge 10 minutes before serving for best texture.

Using the parchment overhang, lift the dessert from the pan and place on a cutting board. Wipe a large knife clean between cuts and slice into 8 squares. Serve each piece warm or at room temperature so the molten center remains luscious.