Ingredients:
6 tablespoons unsalted butter
1/2 cup sugar
6 large eggs, separated
Confectioners sugar
8 oz bitter- or semi-sweet chocolate, finely chopped
Directions:
- Preheat oven to 275 F with rack in the center. Butter bottom and sides of a 9-inch springform pan, then set aside.
- Place butter and chocolate in a large heatproof bowl and microwave in 30-second increments, stirring each time, until completely melted. Let cool slightly, then whisk in egg yolks.
- In a large bowl, beat egg whites until soft peaks form. Gradually add granulated sugar and continue beating until glossy stiff peaks form. Whisk 1/4 of egg whites into chocolate mixture, then gently fold in remaining egg whites.
- Pour batter into prepared pan, and smooth the top with a rubber spatula. Bake until cake pulls away from sides of the pan and is set in the center, 45-50 minutes. Cool completely on a wire rack; remove sides of pan. Serve at room temperature, dusted with confectioners sugar. Serve with whipped cream, if desired.