Preheat the oven to 200°C. Keep 6 ramekins or dariole moulds handy.
1. Grease the ramekins or moulds with butter and dust with cocoa powder. Shake to ensure the cocoa powder sticks evenly to the butter then shake out any excess.
2. Put the chocolate and butter in a saucepan and heat over low heat, stirring continuously until everything has melted. Remove from the heat and set aside.