Preheat your oven to 425°F (220°C) and grease four ramekins with butter, dusting them with cocoa powder.

Melt the chocolate and butter in a microwave-safe bowl in short bursts until smooth.

In another bowl, whisk together eggs, egg yolks, sugar, and vanilla until frothy.

Gently fold the melted chocolate mixture into the egg mixture; sift in flour and mix until just combined.

Pour the batter evenly into the prepared ramekins. Bake for 12-14 minutes until edges are firm but centers remain soft.

Let cool slightly before serving. Dust with powdered sugar or serve with ice cream.