Preheat oven to 425*F.
Grease 6-8 (6oz) ramekins (oven safe custard cups) with butter, or non-stick cooking spray. Then dust with cocoa powder. You can fill 6 dishes full, or 8 dishes 3/4 full.
Melt the chocolate and butter in the microwave, or in a double boiler. I melt mine in the microwave for 1 minute, then stir and heat for another 30 seconds if I need to.
Stir the melted chocolate and butter until smooth, then add the flour and sugar and stir just a couple times.
Add in the eggs, yolks, and vanilla, and stir until incorporated and smooth.
Divide the batter as evenly as possible among the ramekins.
Bake 14 minutes if using 6 dishes, or 12 minutes if batter is divided into 8 dishes. The edges should be firm, but the center will be loose. We always do 8 dishes. I like to check mine around 11 minutes, I usually end up baking them another 1 1/2 - 2 minutes.
Allow to cool 1-2 minutes. Enjoy directly from the dish, or run a knife around the edges of the dish, and invert onto a dessert plate.
Dust with powdered sugar, or serve with whipped cream or vanilla ice cream.
Optional toppings: fresh blueberries, raspberries, blackberries or fresh whip cream. I love mine with fresh blackberries.