01 - Preheat oven to 425°F. Butter four 6 oz ramekins generously and dust with cocoa powder, tapping out excess.
02 - Combine chocolate and butter in a heatproof bowl over barely simmering water, stirring until smooth. Remove from heat and cool slightly.
03 - In a separate bowl, whisk eggs, egg yolks, and sugar until pale and thick, approximately 2 to 3 minutes.
04 - Fold the melted chocolate mixture into the egg mixture. Gently incorporate flour and salt until just combined.
05 - Divide batter evenly among prepared ramekins and arrange them on a baking sheet.
06 - Bake for 10 to 12 minutes, until edges are set and centers remain soft. Avoid overbaking to maintain molten centers.
07 - Let cakes rest for 1 minute. Run a knife around the edges and invert each cake onto serving plates.
08 - Serve immediately with a generous scoop of vanilla bean ice cream.