Preheat and prepare. Heat your oven to 425°F (220°C). Generously butter the ramekins, then dust with cocoa powder, tapping out the excess. This helps the cakes release cleanly and adds flavor.

Melt chocolate and butter. In a heatproof bowl, combine the chopped chocolate and butter. Melt over a saucepan of gently simmering water (double-boiler style), stirring until smooth. Alternatively, microwave in 20–30 second bursts, stirring between each until just melted.

Whisk eggs, yolks, and sugar. In a separate bowl, whisk the eggs, egg yolks, and sugar until slightly thickened and pale, about 1 minute by hand. You’re aiming for a light, glossy mixture.

Combine and flavor. Slowly pour the warm chocolate-butter mixture into the egg mixture, whisking constantly. Stir in the vanilla and salt until evenly combined.

Fold in the flour. Sift the flour over the batter and gently fold with a spatula just until no streaks remain. Do not overmix; a light hand keeps the centers tender.

Fill the ramekins. Divide the batter evenly among the prepared ramekins, filling them about three-quarters full. Place the ramekins on a baking sheet for easy handling.

Bake. Bake for 10–12 minutes. The edges should look set and slightly puffed, but the centers will still look soft and a bit shiny. A tiny wobble in the center is perfect.

Rest briefly. Remove from the oven and let the cakes sit for 1 minute. This helps them firm up just enough to unmold without losing the molten center.

Unmold and serve. Run a thin knife around the edges. Invert each ramekin onto a small plate, wait 10 seconds, then lift the ramekin. Dust with powdered sugar and add ice cream or berries if you like. Serve immediately while warm and gooey.