Preheat your smart oven to 375°F (190°C). Grease two ramekins with butter and dust with cocoa powder to prevent sticking.

Melt the dark chocolate and butter together in a microwave-safe bowl in 30-second intervals, stirring until smooth.

In a separate bowl, whisk together the sugar, egg, egg yolk, and vanilla extract until well combined.

Gradually fold the melted chocolate mixture into the egg mixture, stirring gently until fully incorporated.

Sift in the flour and salt, then fold gently until just combined. Be careful not to overmix.

Divide the batter evenly between the prepared ramekins. Place them in the preheated smart oven and bake for 10-12 minutes.

Remove the cakes when the edges are set but the center is still slightly jiggly. Let them rest for 1 minute.

Carefully invert each ramekin onto a plate. Dust with powdered sugar and garnish with fresh berries before serving.