For the coating: zest the lime. Mix the zest with the sugar and rub between the palms of your hands. Spread a thin layer on a non-stick baking tray and leave to dry overnight.
Cut the butter into small pieces and leave to soften at room temperature. Chop up the chocolate. Bring the creme fraiche to the boil and grate in some of the lime zest. Infuse for ten minutes.
Pour the juice of the lime and the honey into a pan and warm without boiling. Pour the creme fraiche over the chocolate and stir until melted, then add the lime juice and honey. Add the butter and stir until you obtain a thick ganache. Chill in the fridge.
Add the cocoa powder to the sugar coating. Shape the truffles and roll in the cocoa and lime sugar before serving.
«The coating for these truffles needs to be prepared a day in advance.»