Frosty Pumpkin Dessert

32 gingersnap cookies, finely chopped (1 1/3 cups crumbs)
1/4 cup butter or margarine, melted
1 container (1/2 gallon) vanilla ice cream, divided
2 1/2 cups thawed, frozen whipped topping, divided
2/3 cup toffee bits
1 cup solid pack pumpkin
1/3 cup packed brown sugar
1 1/2 teaspoons cinnamon

1. Chop cookies. Place butter in microwave on high 30-40 seconds or until melted. Stir in crumbs. Firmly press crumb mixture onto bottom of Springform pan. Place in freezer.
2. Scoop half of the ice cream into a bowl. Place in refrigerator 10 minutes to soften.
3. Fold 1 cup of the whipped topping and toffee bits into softened ice cream just until blended. Spread evenly over crust. Freeze until firm, about 1 hour.
4. Place remaining ice cream in refrigerator 10 minutes to soften. Meanwhile, mix pumpkin, brown sugar and cinnamon in a bowl. Scoop softened ice cream into pumpkin mixture. Mix just until blended. Spread evenly over ice cream layer. Freeze until firm, about 8 hours or overnight.
5. When ready to serve, place dessert in refrigerator 20 minutes for easier slicing. Run a knife around outside of dessert, remove collar from springform pan. Smooth sides with spreader. Cut dessert into wedges. Garnish each serving with whipped topping and sprinkle with additional cinnamon, if desired.