1 stick butter
4 oz bittersweet chocolate, chopped
2 eggs
2 egg yolks
¼ c sugar
2 t flour
Melt chocolate and butter together in microwave.
While that's melting, beat together eggs, yolks and sugar until light and thick.
Pour egg mixture into melted butter and chocolate, quickly beat in flour until just combined.
Divide among 4 ramekins.
You can butter and flour them if you want to take them out of the mold, but I usually just keep them in the ramekins for serving. At this point, you can refrigerate the cakes until you are ready to cook them but bring them back to room temp before baking.
Preheat oven to 450. Bake cakes for about 10 minutes.