Directions

1. Preheat oven to 450 degrees.
2. Butter four 4-ounce ramekins and lightly dust the inside of each ramekin with cocoa powder, tilting to coat; tap out any excess and set aside.
3. Heat butter and chocolate in heatproof bowl set over (but not touching) simmering water until chocolate is almost completely melted.
4. Meanwhile, in the bowl of an electric mixer fitted with the whisk attachment, whisk together eggs, egg yolks, and sugar until light and thick.
5. Slowly add butter mixture to mixer; add flour and mix until well combined. Divide batter between prepared ramekins. Place ramekins on a baking sheet and transfer to oven. Bake until sides are set and center is soft, 7 to 10 minutes.
6. Invert each mold onto a plate and let stand for about 10 seconds. Gently tap the tops of molds and carefully lift to remove. Sprinkle with confectioners' sugar, if desired; serve immediately.