- 8 ounces bittersweet (not unsweetened) or semisweet chocolate, chopped
- 6 tablespoons (3/4 stick) unsalted butter
- 6 large eggs, separated
- 1/2 cup sugar
- 1/3 cup water
- 4 ounces bittersweet (not unsweetened) or semisweet chocolate, cut into 8 pieces total
- Preheat oven to 375°F. Butter and flour eight 3/4-cup soufflé dishes. Stir 8 ounces chopped chocolate and butter in heavy medium saucepan over low heat until melted and smooth. Pour into large bowl. Whisk in yolks. Set chocolate mixture aside.
- Stir sugar and water in heavy small saucepan over low heat until sugar dissolves. Increase heat and boil without stirring until candy thermometer registers 236°F swirling pan occasionally, about 5 minutes.
- Meanwhile, beat egg whites in another large bowl to soft peaks.
- Gradually beat boiling syrup into whites in slow steady stream. Continue beating until stiff, about 3 minutes. Fold whites into chocolate mixture in 3 additions. Divide soufflé mixture among prepared dishes. Place 1 chocolate chunk in center of each, pressing to submerge. (Can be prepared 1 day ahead. Cover with plastic wrap and refrigerate.)
- Bake soufflés until slightly puffed and softly set, about 15 minutes. Serve immediately.