If you can melt butter, you can make these cakes. Be brave and pull them out of the oven while they’re still squidgy in the middle, for a dense, fudgy, heavenly treat.
Heat the oven to 180°C/Gas 4. Roughly chop the chocolate. Fit a heatproof bowl over a saucepan of simmering water, and combine the chocolate, sugar and butter in the bowl. Stir as it melts into a smooth, glossy sauce. Remove from heat and cool for 5 minutes.