bittersweet (not unsweetened) or semisweet chocolate, chopped
unsalted butter (1 1/4 sticks)
large egg yolks
All Purpose Flour
Preheat oven to 450°F.
Butter six 3/4-cup soufflé dishes or custard cups.
Stir chocolate and butter in heavy medium saucepan over low heat until melted. Cool slightly.
Whisk eggs and egg yolks in large bowl to blend.
Whisk in sugar, then chocolate mixture and flour. Pour batter into dishes, dividing equally. (Can be made 1 day ahead. Cover; chill.)
Bake cakes until sides are set but center remains soft and runny, about 11 minutes or up to 14 minutes for batter that was refrigerated. Run small knife around cakes to loosen. Immediately turn cakes out onto plates.