01 - Preheat oven to 425°F. Grease four 6 oz ramekins with butter and dust with cocoa powder, tapping out excess.
02 - Melt chocolate and butter together in a heatproof bowl set over simmering water, stirring until smooth. Remove from heat and let cool slightly.
03 - In a separate bowl, whisk together sugar, eggs, and egg yolks until thick and pale.
04 - Stir melted chocolate mixture into egg mixture. Add vanilla extract and salt.
05 - Sift in flour and gently fold until just combined. Do not overmix.
06 - Divide batter evenly among prepared ramekins. Place ramekins on a baking sheet.
07 - Bake for 11-12 minutes until edges are set but centers are still soft. Do not overbake.
08 - While cakes bake, combine raspberries, sugar, lemon juice, and water in a saucepan over medium heat. Cook 5 minutes, stirring, until raspberries break down.
09 - Strain coulis through a fine sieve into a bowl to remove seeds. Let cool.
10 - Remove cakes from oven. Let rest 1 minute, run knife around edges and invert onto serving plates. Dust with powdered sugar, drizzle with coulis, and garnish with raspberries and mint. Serve immediately.