Preheat oven to 200°C (400°F). Grease ramekins with butter and cocoa.

Melt chocolate and butter together until smooth.

Whisk eggs and sugar until thick and pale.

Fold in melted chocolate mixture, then sift in flour.

Pour into ramekins and bake for 10-12 minutes until edges are set but center is soft.

Serve immediately with vanilla ice cream.