COMBINE pumpkin, pudding mix, evaporated milk and pumpkin pie spice in large mixer bowl; beat for 1 minute or until blended. Fold in 1 1/2 cups whipped topping. Spoon into crust. Freeze for at least 4 hours or until firm. Let stand in refrigerator for 1 hour before serving. Garnish with remaining whipped topping and raspberries, if desired. Serve immediately.