Place chocolate and butter in a heat-proof bowl. Set aside..

Heat the heavy cream until it is simmering over medium heat. Just until bubbles form around the edge of the pan.

Add the butter to the chocolate and pour the heavy cream evenly on top. Let the warm cream and chocolate sit for 5 minutes minutes. Add the vanilla extract then stir until the chocolate has completely melted. Place a piece of plastic wrap directly on the surface (to avoid condensation) and refrigerate for 1-2 hours. 

Scoop the set truffle mixture into 2 teaspoon-sized mounds. Roll each into balls.

Roll each into desired toppings. Store, covered tightly, at room temperature for 3-4 days or refrigerate up to 2 weeks.