Prep the ramekins. Grease 4 small ramekins (6-ounce size) with butter. Dust with cocoa powder, tapping out the excess. This prevents sticking and keeps the outside dark and pretty.

Preheat the air fryer. Set it to 375°F (190°C) for 3–5 minutes. A hot basket ensures a firm exterior and molten center.

Melt the chocolate and butter. In a heatproof bowl, microwave butter and chocolate in 20–30 second bursts, stirring between each, until smooth. You can also use a double boiler. Let it cool for 2–3 minutes so it doesn’t scramble the eggs.

Whisk the eggs and sugar. In a separate bowl, whisk eggs, egg yolks, and sugar until the mixture looks thick and slightly pale, about 30–45 seconds by hand. Whisk in the vanilla and salt.

Combine wet ingredients. Slowly stream the melted chocolate mixture into the egg mixture while whisking. You want a glossy, unified batter.

Fold in the dry ingredients. Sift the flour and cocoa powder over the bowl. Gently fold with a spatula just until no dry streaks remain. Do not overmix or the cakes can turn dense.

Fill the ramekins. Divide the batter evenly among the prepared ramekins, filling each about 3/4 full.

Air fry. Place ramekins in the basket with space between them. Cook at 375°F (190°C) for 6–8 minutes. The tops should look set and slightly puffed, but the centers should still feel soft when lightly pressed.

Rest briefly. Let the cakes sit for 1–2 minutes. This helps them finish setting without losing the molten center.

Unmold and serve. Run a thin knife around the edges, invert onto plates, and lift off the ramekins. Dust with powdered sugar and add a scoop of ice cream or berries if you like. Serve immediately for that perfect lava flow.