01 - Preheat the oven to 425°F. Generously butter 4 ramekins (approximately 6 oz each) and lightly dust with cocoa powder, tapping out excess.
02 - Melt the chocolate and butter together in a heatproof bowl set over a pot of simmering water, stirring until smooth. Remove from heat and allow to cool slightly.
03 - In a separate bowl, whisk together eggs, egg yolks, and powdered sugar until thick and pale.
04 - Fold the melted chocolate mixture into the egg mixture. Gently stir in the flour, vanilla extract, and salt until just combined.
05 - Divide the batter evenly among the prepared ramekins. Place ramekins on a baking tray.
06 - Bake for 11-12 minutes, until the edges are set but centers remain soft. Do not overbake.
07 - While cakes bake, combine raspberries, sugar, and lemon juice in a small saucepan. Cook over medium heat until raspberries break down (3-4 minutes). Remove from heat, puree with an immersion blender or food processor, and strain through a fine sieve to remove seeds.
08 - Remove cakes from oven and let rest for 1 minute. Run a knife around the edges and invert each cake onto a dessert plate. Drizzle with raspberry coulis, garnish with fresh raspberries, and dust with powdered sugar. Serve immediately.