1. Spread 2 cups ice cream in bottom of crust; drizzle with 2 tablespoons chocolate syrup, and sprinkle with 2 tablespoons toffee bits. Spread remaining ice cream over toffee bits. Freeze 8 hours or until firm.
2. Top pie with whipped topping, and drizzle with remaining 2 tablespoons syrup; sprinkle with remaining 2 tablespoons toffee bits.