01 - Place the finely chopped dark chocolate in a heatproof bowl.
02 - In a small saucepan, gently heat the heavy cream over medium heat until it just begins to simmer, ensuring it does not boil.
03 - Pour the hot cream over the chopped chocolate. Allow it to stand undisturbed for 2 minutes, then gently stir until the chocolate is fully melted and the mixture is smooth.
04 - Add the room-temperature butter and continue to stir until it is completely incorporated and the ganache appears glossy. If desired, stir in the vanilla extract and liqueur at this stage.
05 - Cover the bowl tightly with plastic wrap, ensuring it touches the surface of the ganache to prevent a skin from forming. Refrigerate for a minimum of 2 hours, or until the ganache is firm enough to handle.
06 - Line a baking sheet with parchment paper to prevent sticking.
07 - Using a small spoon or melon baller, scoop out consistent portions of the chilled ganache. Gently roll each portion between your palms to form smooth, round truffles. (Wearing food-safe gloves is recommended for this step).
08 - Roll each formed truffle thoroughly in your chosen coating: unsweetened cocoa powder, finely chopped toasted nuts, or grated coconut. Place the coated truffles onto the prepared baking sheet.
09 - Refrigerate the truffles for an additional 30 minutes before serving. Store any remaining truffles in an airtight container in the refrigerator for up to 1 week.