1. Heat the cream until it just comes to a boil, add the chopped chocolate, and remove the saucepan from the heat.
2. Stir the mixture with a rubber spatula until the chocolate is completely melted.
3. Stir in the butter until the ganache is smooth.
4. Put the ganache in a bowl and cover with plastic wrap, ensuring that the plastic makes contact with the entire surface of the ganache.
5. Refrigerate at least one hour (or overnight) until the ganache is set.
6. To form the truffles, use a melon baller to scoop the ganache into a ball and place on a wax paper-lined baking sheet.
7. Finish the truffles by dipping in your ingredient of choice. If dipping in chocolate, place the balls of ganace in the refrigerator or freezer for at least one hour or until thoroughly chilled before dipping.