Heat chocolate squares and butter in a saucepan over medium-low heat, stirring constantly, until melted. Remove from heat; stir in cream. Let cool 5 minutes. Stir in pecans. Cover and chill 2 hours or until mixture is firm.
Shape chocolate mixture into 1" balls; roll in crushed toffee candy. Store truffles in refrigerator up to one week.
Note: Crush toffee bars easily by sealing them in a heavy-duty, zip-top plastic bag, crush with a rolling pin. Use a 1 1/4" metal scoop to shape into truffles. It streamlines the process.