01 - Place the chopped dark chocolate in a medium heatproof bowl.
02 - Warm the heavy cream in a small saucepan over medium heat until it just begins to simmer; remove from heat immediately.
03 - Pour the hot cream over the chopped chocolate and let sit for 2 minutes. Add the softened butter and vanilla extract, then stir gently until the mixture is smooth and homogenous.
04 - Cover the bowl and refrigerate for at least 2 hours until firm enough to scoop.
05 - Scoop small portions using a melon baller or teaspoon and quickly roll each into a ball by hand.
06 - Roll each truffle in your choice of unsweetened cocoa powder, chopped toasted nuts, or shredded coconut to coat evenly.
07 - Arrange the coated truffles on a parchment-lined tray and refrigerate for 20 minutes to firm up before serving.