Preheat your oven to 400°F (200°C). Generously grease four 6-ounce ramekins with butter. Dust the insides with a light coating of cocoa powder or flour, tapping out any excess. This is key for easy release later.

In a heatproof bowl set over a saucepan of simmering water (or a microwave safe bowl), melt the butter and chopped chocolate together, stirring until completely smooth. Remove from heat and let cool slightly for a few minutes.

In a separate medium bowl, whisk together the whole eggs, egg yolks, granulated sugar, and vanilla extract until the mixture is light yellow and slightly thickened. This usually takes about 2-3 minutes.

Gradually add the slightly cooled chocolate mixture to the egg mixture, stirring gently until just combined. Be careful not to overmix.

Fold in the flour until just incorporated. Divide the batter evenly among the prepared ramekins.

Here's the secret to that perfectly molten center: Place the ramekins on a baking sheet and bake for 12 to 14 minutes. The exact time will depend on your oven and ramekin size. You are looking for the edges to be set and firm, but the very center should still appear soft and jiggly when gently shaken. This delicate balance ensures the outside is cooked while the inside remains gloriously liquid. Do not overbake!

Carefully remove the ramekins from the oven. Let them cool for just 1 minute. Run a thin knife around the edge of each cake, then invert each onto a serving plate. Dust with powdered sugar and serve immediately with a scoop of vanilla ice cream. Enjoy that amazing chocolate flow!