Preheat oven to 400˚F. Grease six 4-ounce ramekins well with cooking spray, place them on a baking sheet and set aside. Melt the chopped chocolate and butter in the microwave on high. Stir until smooth.

Whisk in the powdered sugar, eggs, egg yolks, and vanilla.

Put the flour and cocoa powder into a sifter and sift into the bowl. Stir until combined.

Divide the batter between the six prepared ramekins.

Bake at 400˚F for 12-14 minutes until the sides are firm, yet the centers are still soft but not jiggy. The molten chocolate center should reach 160˚F with an instant-read thermometer.

Remove from oven and let stand for 3 minutes. Run a thin knife around the edges to loosen and invert onto serving plates. Dust with powdered sugar, if desired.