Chop chocolate into small pieces then place in a heat proof bowl and set aside.

Warm cream and butter in a saucepan until it comes to a boil. Immediately pour over the chopped chocolate and stir until the chocolate has melted.

Pour this mixture (which is called ganache) into a casserole dish and leave to cool. Once the ganache has cooled to room temperature, cover with plastic wrap and place in the fridge for about two hours.

Once the ganache has hardened, remove from the fridge. Use a melon baller or round measuring spoon to scrape about 2 teaspoons worth of hardened ganache out of the casserole pan and quickly roll into a ball. Roll the ball in the cocoa powder and set aside on a tray.

If the mixture becomes too soft to work with, put it back in the fridge to harden. Dusting your hands with cocoa powder can also help as you roll the balls.

Store truffles in the fridge for up to a week.

Truffles can also be rolled in shredded coconut or chopped nuts.