In a small pot, heat the heavy cream until it starts steaming.

Put bittersweet chocolate pieces in bowl, pour the hot cream on top and stir until chocolate is melted and well incorporated into the cream.

Chill mixture until solid all the way through, at least one hour.

Using a chilled melon baller or latex gloves, scoop out a tablespoon of the mixture and roll it into a ball. Place on a baking sheet and repeat until mixture is all balled. If mixture becomes too soft, rechill in refrigerator or freezer for a few minutes.

After truffles are balled, pour cocoa powder onto a plate. Roll each truffle in the cocoa powder. Can also use confectioner's (powdered) sugar or a cinnamon/sugar mix.

Serve immediately or wrap in plastic wrap and store in the refrigerator for up to four days.