Directions:

Butter eight 3/4 cup ramekins or custard cups; dust with sugar. Arrange dishes on rimmed baking sheet.

Melt 2 tablespoons butter in heavy medium saucepan over medium heat. Add 2 tablespoons flour; whisk until mixture is bubbling, about 1 minute. Increase heat to medium-high. Gradually whisk in 1 cup milk. Cook until mixture thickens and boils, whisking constantly, about 2 minutes. Remove from heat. Add bittersweet chocolate, 4 tablespoons sugar, and unsweetened chocolate; whisk until melted and smooth. Pour souffle base in to large bowl. Cool to room temperature, stirring occasionally.

Whisk egg yolks into soufffle base. using electric mixer, beat egg whites and salt in medium bowl unti soft peaks form. Gradually add remaining 2 tablespoons sugar, beating until stiff and glossy. Fold 1/4 of whites into souffle base. Fold in remaining whites in 2 additions. Divide souffle mixture among prepared ramekins. (Can be prepared ahead. Cover and refrigerate up to 2 days or freeze up to 1 week; do not thaw frozen souffles before baking.)

Preheat oven to 400. Bake souffles uncovered on rimmed baking sheet until puffed and centers move slightly when baking sheet is shaken gently, about 17 minutes for fresh or chilled souffles or 22 minutes for frozen.

Serve chocolate souffles immediately with sweetened whipped cream.