Chocolate Avalanche Recipe

Prepare

Preheat the oven to 350°F (175°C). Grease two 9-inch round cake pans and line the bottoms with parchment; lightly grease parchment and dust with cocoa or flour.

Whisk together dry ingredients: in a large bowl, sift or whisk the flour, granulated sugar (1.75 cups), cocoa powder, baking powder, baking soda, and salt until evenly combined.

Combine wet ingredients: in a separate bowl, whisk the eggs, buttermilk, warm water, vegetable oil, and vanilla extract until smooth.

Mix batter: pour the wet ingredients into the dry and stir until just combined. Scrape down the bowl and briefly beat to ensure there are no large lumps. The batter will be fairly thin from the warm water and oil.

Divide and bake: divide batter evenly between the two prepared pans. Smooth the tops. Bake in the preheated oven 25–30 minutes, or until a toothpick inserted in the center comes out with a few moist crumbs but not wet batter.

Cool: remove cakes from oven and let cool in pans on a wire rack 10 minutes. Run a knife around the edges, invert onto racks, remove parchment, and let cool completely before assembly (at least 1 hour).

Melt chocolate: place the chopped dark chocolate (10 oz) in a heatproof bowl. Heat 0.5 cup of the heavy cream until steaming (do not boil) and pour over the chocolate along with the instant espresso. Let sit 1 minute, then stir until smooth. Stir in the butter and salt. Set aside to cool slightly.

Temper egg yolks: in a small saucepan or microwave-safe bowl, whisk the 3 egg yolks with the 0.25 cup sugar until smooth. Very slowly whisk in about 2 tbsp of the hot cream from the chocolate mixture to temper the yolks, then gradually whisk the tempered yolks back into the remaining warm cream (if you still have warm cream reserved).

Combine and chill: if the chocolate mixture was all combined with the cream earlier, simply whisk the tempered yolk mixture into the chocolate mixture until fully incorporated. Allow mixture to cool to room temperature, then chill in the fridge until slightly set but still spoonable, about 30–45 minutes.

Whip remaining cream: whip the remaining 1 cup of heavy cream to soft peaks. Fold about one-third of the whipped cream into the cooled chocolate base to loosen it, then gently fold in the remaining whipped cream until a homogeneous mousse forms. Do not overfold; keep it light.

Refrigerate: refrigerate the mousse until firm enough to spread, about 30 minutes more if needed.

Heat cream: place semisweet chocolate (10 oz) in a heatproof bowl. Heat 1 cup heavy cream with 1 tbsp light corn syrup until it just begins to simmer. Pour the hot cream over the chocolate and let sit 1 minute.

Make ganache: stir gently until chocolate is melted and smooth. Stir in 2 tbsp butter and 1/4 tsp sea salt until glossy. Let the ganache cool and thicken at room temperature about 15–20 minutes, or chill briefly to reach a pourable but thick glaze consistency.

Level layers: if cake tops domed, level them with a serrated knife so layers stack evenly. Place one cake layer on your serving plate or cake board.

Spread mousse: using an offset spatula, spread about half of the chilled chocolate mousse over the first cake layer in an even layer (about 1 to 1 1/4 inches).

Top with second layer: place the second cake layer on top gently and press lightly to adhere. Chill the stacked cake 15 minutes to set the mousse slightly.

Pour ganache: when ganache is thick but pourable, pour it over the chilled cake starting at the center and working outward so it drips over the sides. Use an offset spatula to smooth the top and encourage even drips down the sides.

Chill to set: refrigerate the cake 20–30 minutes until ganache is set but not rock hard.

Finish and garnish: pipe or dollop whipped cream around the top edge if desired. Sprinkle chocolate shavings/curls and chopped toasted nuts over the top and edges. Dust very lightly with cocoa powder if using.

Serve: let the cake sit at room temperature 10–15 minutes before slicing for cleaner cuts. Use a hot, clean knife wiped between slices.