Place 16 ounces of chocolate in a large glass bowl.
In a saucepan, heat the cream to 90-110°F, then pour it over the chocolate and let sit for a few minutes.
Whisk until the chocolate is smooth and melted. (If needed, microwave for 30 seconds at a time or use a double boiler.)
Stir in the rum or another flavoring of your choice until well combined.
Pour the chocolate mixture into pan lined with parchment or plastic wrap. Refrigerate for 60 minutes, until thick and "scoopable."
Scoop small balls onto a parchment-lined baking sheet. Roll quickly between your hands to form round truffles, then freeze for 60 minutes.
Melt 23 ounces of chocolate over a double boiler until smooth.
Dip each truffle in melted chocolate, place on parchment to set, and add sprinkles, nuts, or gold dust if desired.