Preheat the Oven: Preheat your oven to 425°F (220°C). Grease 4 (6-ounce) ramekins or muffin cups and dust with cocoa powder to prevent sticking.

Melt Chocolate and Butter: In a microwave-safe bowl, melt the chopped chocolate and butter together in 30-second intervals, stirring in between until smooth. Set aside to cool slightly.

Whisk Eggs and Sugar: In a separate bowl, whisk the eggs, egg yolks, vanilla, and powdered sugar until light and fluffy.

Combine: Gradually add the melted chocolate mixture to the egg mixture, stirring until fully combined.

Add Dry Ingredients: Fold in the flour and a pinch of salt, stirring just until combined and smooth.

Fill Ramekins: Divide the batter evenly among the prepared ramekins, filling each about ¾ of the way.

Bake: Bake for 12-14 minutes, or until the edges are firm but the center is still soft. The top should be set, but the inside will be molten.

Rest and Serve: Let the cakes rest for 1-2 minutes, then run a knife around the edges and carefully invert each cake onto a plate. Serve immediately, ideally with a scoop of ice cream or whipped cream.