12 ounces bittersweet (not unsweetened) chocolate, chopped (you can also use semi-sweet chocolate)
¾ cup (1 ½ sticks) unsalted butter, cut into pieces
6 large eggs, separated
12 tablespoons sugar
2 teaspoons vanilla extract
Serve with whipped cream, ice cream, and/or make a raspberry sauce (frozen raspberries, lemon juice, and maple syrup in a food processor until well blended)
- Preheat oven to 350°F.
- Butter 9-inch-diameter springform pan. Line bottom of pan with parchment paper; butter the paper. Wrap outside of pan with foil.
- Stir chocolate and butter in heavy medium saucepan over low heat until melted and smooth. Remove from heat. Cool to lukewarm, stirring often.
- Using electric mixer, beat egg yolks and 6 tablespoons sugar in large bowl until mixture is very thick and pale, about 3 minutes.
- Fold lukewarm chocolate mixture into yolk mixture, then fold in vanilla extract.
- Using clean dry beaters, beat egg whites in another large bowl until soft peaks form. Gradually add remaining 6 tablespoons sugar, beating until medium-firm peaks form. Fold whites into chocolate mixture in 3 additions. Pour batter into prepared pan.
- Bake cake until top is puffed and cracked and tester inserted into center comes out with some moist crumbs attached, about 50 minutes. Cool cake in pan on rack (cake will fall).
- Gently press down crusty top to make evenly thick cake. Using small knife, cut around pan sides to loosen cake. Remove pan sides. Place 9-inch-diameter tart pan bottom or cardboard round atop cake. Invert cake onto tart pan bottom. Peel off parchment paper.