Using a food processor or heavy French chef’s knife, chop the chocolate very fine.

In a heavy small pan, heat the cream over low heat until quite hot but not boiling. Set the cream aside for about 1 minute. Add the chocolate pieces all at once, gently covering them in the hot cream with a spoon. When the pieces are soft, stir with rubber spatula until the mixture is smooth and blended. If there are still pieces that are not completely melted, briefly place pan in a larger container of hot water, being careful not to get any hot water into the chocolate mixture.

Add two tablespoons of soft sweet butter, cinnamon and vanilla extract and blend until completely incorporated.

Cover mixture loosely and refrigerate, stirring occasionally, until a spoon of ganache dropped into the mixture holds its shape, about 30 minutes to an hour.

Scoop the truffle mixture with a melon baller or small spoon into small balls onto a baking sheet, keeping each truffle about the same size. Refrigerate until firm, about 30 minutes.Roll each small mound into a ball between your palms, then roll the ball into the cocoa powder until it is completely covered.

Place the truffles in small fluted candy cups if available, or package them in small boxes or bags. They can be served at once or stored in the refrigerator for up to 1 month.