Place the chopped dark chocolate and butter in a heatproof bowl and set aside.

In a small saucepan, gently heat the heavy cream over medium heat until it begins to steam but does not boil. Carefully pour the hot cream over the chocolate and butter in the bowl, ensuring it fully covers the chocolate. Let the mixture sit undisturbed for 2 minutes.

After the resting period, whisk the ingredients together until the ganache becomes smooth and glossy. Cover the bowl and refrigerate the ganache for at least 2 hours or until it is firm enough to handle. For convenience, chilling overnight works as well.

Using a tablespoon measure, scoop out portions of the firm ganache. Gently roll each portion between your palms to form smooth, round truffle shapes. Arrange the truffles on a lined baking sheet.

You can leave the truffles plain or coat them for a decorative touch. Roll them in cocoa powder for a classic finish, sprinkle them with colorful decorations, or dip them in melted chocolate and top with crushed candy canes for a festive twist.

Store the truffles in an airtight container in the refrigerator until ready to serve. Serve chilled for a firmer texture or allow them to come to room temperature for a softer, melt-in-your-mouth experience.