In a large mixing bowl, combine half and half and instant pudding mix.

Whisk the mixture for 1 minute until well combined.

Let the mixture stand for 5 minutes to thicken.

Gently fold in the whipped topping, chopped pecans, gingersnaps, pumpkin, and pumpkin pie spice.

Spoon the mixture into the graham cracker crumb crust.

Freeze the pie until firm, approximately 3 hours.

Let the pie stand at room temperature for 10 minutes to soften slightly before serving.

Store any leftovers in the freezer.