While pumpkin pie deserves respect as a Thanksgiving icon, it's fun to shake up tradition. Surprise your family and friends with a frozen pie this year — it just might become one of their holiday favorites. No need to let them know how easy it is.
Preheat the oven to 350 degrees. Coat a 9-inch deep-dish pie pan with cooking spray.
Combine the gingersnaps and raisins in a food processor and pulse until chopped finely. Add the oil and pulse until blended. Press evenly into the bottom and up the sides of the prepared pan. Bake the crust until set, about 10 minutes. Transfer to a wire rack to cool completely.
Combine the pumpkin, sugar, cinnamon, ginger, and nutmeg in a large bowl and mix well. Add the ice cream and stir until blended. Spoon the mixture into the cooled pie crust.
Freeze until firm, at least 2 hours. Let the pie soften slightly in the refrigerator for 20-30 minutes before serving.