1/3 cup dark cocoa powder about 30 grams, sifted if lumpy
4 large eggs, separated
1 cup granulated sugar 200 grams
1/2 teaspoon vanilla extract (optional)
2 pinches sea salt
Equipment
oven
9-inch round cake pan
parchment paper
3-quart saucepan
medium bowl
large bowl
whisk
electric beater
Directions
Heat oven to 350°F. Butter a 9-inch round cake pan. Line the bottom with parchment paper.
Melt butter in a 3-quart saucepan over medium heat. Once melted, remove from heat and stir in chopped chocolate until melted.
Add 2 tablespoons water, baking powder, flour, and cocoa. Stir until just combined.
In a medium bowl, whisk egg yolks with sugar, 1 tablespoon water, and vanilla (if using) until pale.
Stir egg yolk mixture into chocolate mixture until just combined.
In a separate clean bowl, beat egg whites with salt until stiff peaks form.
Gently fold egg whites into chocolate mixture until streaks disappear. Do not deflate the mixture.
Pour batter into the prepared pan. Bake for 25 to 30 minutes or until a toothpick inserted in the center comes out clean.
Let cake rest on a rack for 5 minutes. Run a knife along the edge, invert onto a rack, then flip onto a plate. Serve warm or cold.
For layer cake: Prepare chocolate whipped cream by heating 1 cup cream to a simmer, whisking in 6 oz chocolate until smooth. Add 1 cup cold cream. Chill 4-24 hours. Whip before using.
Make twice the cake batter and divide into 3 pans. Bake each for 15-20 mins. Cool completely. Assemble by spreading chocolate whipped cream between layers. Chill until needed.