In a small saucepan, bring the cream to a simmer, stir occasionally.

Meanwhile, place the chopped chocolates and sugar in a separate bowl. Pour the hot cream over them, add the vanilla extract and allow to stand for 30 seconds then stir until smooth.

Refrigerate for at least 3 to 4 hours.

Remove from the refrigerator. Let the chocolate mixture sit at room temperature for about 10 minutes.

Scoop out small balls with a melon baller or spoon. Roll them quickly in your hands (be careful to avoid melting the balls). Roll each ball in the cocoa powder until completely coated. Place them on parchment or waxed paper.

Store the chocolate truffles covered in the refrigerator.