Preheat & Prep: Preheat oven to 425°F. Butter six ramekins and dust with cocoa powder.
Melt Chocolate & Butter: In a microwave-safe bowl, melt chocolate and butter in 15-second intervals, stirring until smooth.
Whip Eggs & Sugar: In another bowl, beat eggs, egg yolks, and sugar until thick and pale. This helps create the cake’s structure.
Combine Mixtures: Slowly whisk the melted chocolate into the egg mixture. Fold in flour and vanilla extract gently, without overmixing.
Fill & Bake: Divide batter into ramekins, filling about ⅔ full. Bake for 12-14 minutes until edges are set, but the center is slightly wobbly.
Rest & Serve: Let cakes rest for 2-3 minutes before loosening edges with a knife. Carefully invert onto plates. Serve warm with ice cream or berries.