Preheat the oven to 200ºC/180ºC fan/ 400ºF/Gas 5.
Grease the sides and base of the moulds and sprinkle them with cocoa powder, then tap to remove any excess.
Divide the chocolate into chunks and melt it over a heatproof bowl set over a pan with simmering water.
Once the chocolate is melted mix in the cream, sugar, eggs, rum and the rice flour, Whisk well and then blend to get a homogeneous cake batter.
Pour into the moulds and bake for around 5 to 6 minutes.