Heat the cream just to the point of simmering. Watch it the whole time, since boiling cream can overflow the pot! Remove from heat right away once it starts to simmer.
Stir in the chocolate and liquor (if using), and keep stirring until the chocolate has melted completely. If using chopped nuts, stir them in now.
Let the mixture cool, then put in the refrigerator.
Check the consistency of the truffle mixture after 2 hours in the refrigerator. You should be able to roll balls from it. If it’s too soft (impossible to roll balls), put it back in the refrigerator and check again after 30 minutes.
Line the baking sheet with parchment paper. Once the truffle mixture is the right consistency, use a spoon to put some of it on your hands, roll into balls and put the balls on the parchment paper.
Put the baking sheet with homemade chocolate truffles in the freezer for 30 minutes. After you remove them from the freezer, put on a plate and enjoy! Store the homemade chocolate truffles in the refrigerator.