01 - Preheat oven to 425°F. Butter four 6 oz ramekins and dust with cocoa powder, tapping out excess.
02 - Combine dark chocolate and butter in a heatproof bowl over simmering water, stirring until smooth. Remove from heat and let cool slightly.
03 - In a separate bowl, whisk eggs, egg yolks, and sugar until pale and slightly thickened.
04 - Gently fold the melted chocolate mixture into the egg mixture until blended.
05 - Sift in flour and salt, folding until just combined. Avoid overmixing.
06 - Divide batter evenly among prepared ramekins.
07 - Place ramekins on a baking sheet and bake for 11 to 12 minutes until edges are set but centers remain soft.
08 - Let cakes sit for 1 minute. Run a knife around edges and invert onto dessert plates.
09 - Serve immediately with a scoop of vanilla ice cream. Optionally dust with powdered sugar and garnish with berries or mint.