Place chopped chocolate in a medium heatproof bowl and set aside.
Heat heavy cream in a small saucepan over medium heat until it just begins to simmer (don't let it boil).
Pour hot cream over the chocolate and let sit for 2 minutes, then stir gently until smooth and glossy.
Stir in butter, vanilla, and salt until completely combined and silky.
Cover the bowl with plastic wrap and refrigerate for 2-3 hours until firm enough to scoop.
Using a small cookie scoop or melon baller, scoop mixture and quickly roll into 1-inch balls with your hands (work fast, they get messy!).
Roll each truffle in cocoa powder or your chosen coating until completely covered.
Store in an airtight container in the refrigerator for up to 2 weeks or freeze for up to 3 months.