Preheat oven to 425°F (220°C) and grease four ramekins generously.

In a microwave-safe bowl, melt chopped chocolate and butter together until smooth, stirring occasionally.

In a separate bowl, whisk together granulated sugar, eggs, and egg yolks until frothy.

Gently fold in the melted chocolate mixture, followed by flour and vanilla extract until just combined.

Divide the batter evenly among the greased ramekins, filling them about three-quarters full.

Bake for 12-14 minutes until edges are firm but centers remain soft.

Let cool for 1 minute before inverting onto plates and dusting with powdered sugar.