Yield: 12 servings
prep Time: 20 minutes
Bake & cooling time: 3 hours, 10 minutes
12 tablespoons (170g) unsalted butter, cut into pieces
6 ½ ounces (184g) dark chocolate, chopped
1 teaspoon vanilla extract
4 large eggs, separated
1 cup (198g) granulated sugar, divided
2 cups (198g) almond flour
½ teaspoon salt
Confectioners sugar for dusting
Preheat oven to 325 degrees. Lightly grease a 9-inch springform pan.
Melt together butter and chocolate in a medium bowl, stirring often, until melted. Stir in vanilla and set aside.
In a large bowl, whip egg whites on medium-low speed until foamy. Increase speed to medium-high and continue to whip, slowly adding ½ cup granulated sugar, until whites are glossy and thick and hold stiff peaks.
In another bowl, beat egg yolks and remaining ½ cup granulated sugar on medium-high speed until thick and pale yellow, scraping down bowl as necessary. Add chocolate mixture and mix on medium speed until incorporated. Add almond flour and salt, and mix until incorporated, scraping sides of bowl as necessary.
Add one-third of whipped whites to bowl and mix on medium speed until no streaks of white remain, scraping down bowl halfway through mixing. Transfer batter to bowl with remaining whites. Gently fold whites into batter until no streaks of white remain. Pour batter into prepared pan, smooth top with spatula, and place pan on rimmed baking sheet.
Bake until toothpick inserted in center comes out with few moist crumbs attached, about 50 minutes. Let cake cool in pan on wire rack for 20 minutes before removing the side of pan. Let cake cool completely, at least 2 hours. Dust with confectioner’s sugar, and serve with whipped cream if desired.