Pour milk into a large bowl. Add pudding mix and pumpkin pie spice. Beat with wire whisk for 1 minute (mixture will be very thick). Add in pumpkin with wire whisk, stir in whipped topping. Pour pumpkin mixture into pie crust.
Refrigerate for 2 hours or until set. Garnish with additional whipped topping.
*May be substituted with 1/2 tsp, ground cinnamon, 1/4 tsp. ground ginger and 1/8 tsp. ground cloves in place of pumpkin pie spice.