Heat the cream – Warm the cream in a small saucepan over medium heat until it starts to steam and small bubbles appear on the edge. Don’t boil.
Pour over chocolate – Place the chopped bittersweet chocolate in a heatproof bowl. Pour the warm cream over it. Let sit for 1–2 minutes.
Stir until smooth – Stir gently with a spatula until the chocolate melts into a silky ganache.
Add butter and vanilla – Stir in butter and vanilla extract until smooth.
Chill – Cover the bowl and refrigerate for about 2 hours, or until firm enough to scoop.
Shape the truffles – Scoop small portions with a spoon and roll into balls with your hands.
Coat – Roll the truffles in cocoa powder, dip in melted chocolate, or coat with nuts. Place on parchment paper until set.
