1 x 250g/9oz tin French crème de marrons
135g/41/2oz dark chocolate (85 per cent cocoa solids)
2 tablespoons Cognac or Armagnac
30-35 coffee beans (optional)
Good-quality cocoa powder
In a small, heavy-bottomed pan, gently heat the crème de marrons. When heated through, break chocolate into pieces and add to the pan bit by bit, stirring thoroughly to melt, until all the chocolate is incorporated. The mixture should be dark and glossy. Do not to let it scorch. Add the Cognac or Armagnac and stir. Chill.
When cool, roll a teaspoon of the mixture into a ball. (For a bitter-sweet flavour, place a coffee bean in the centre before rolling.) Repeat for remaining mixture. Sprinkle cocoa powder into a shallow bowl; roll each truffle in the cocoa powder to finish.