Remove hot cream from heat and pour it over chocolate. Let stand for 1 minute, then stir until chocolate is melted and mixture is smooth. Stir in vanilla extract and chopped toffee bits. Cover and chill until firm, about 2 hours.
Line a rimmed baking sheet with parchment paper. Using a small cookie scoop, shape mixture into 1-inch balls. Roll truffles between your palms to create a smooth appearance. If desired, roll truffles in cocoa powder or additional toffee bits. Chill until ready to serve.
Truffles can be made up to one day in advance; store truffles in an airtight container within the refrigerator.