Pour crumbs into a 9 or 10-inch pie pan and add melted butter; stir well. Reserve some cookie crumbs for garnish, if desired.
Press down using the flat side of a small measuring cup to form pie crust. Bake at 350 for 8 minutes, if desired. Allow to cool completely if baking.
Make the Pumpkin Ice Cream Filling:
While the crust cools, allow the ice cream to set out and soften slightly.
In a large bowl, stir together pumpkin puree, salt, cinnamon, nutmeg, sugar, and vanilla.
Fold in ice cream.
Pour into the Biscoff Cookie Crust, cover filling with plastic wrap directly on top of filling and place in the freezer for 3-4 hours or until firm.
Top with reserved cookie crumbs for garnish, if desired.
Notes
Hint: To slice a frozen pie, dip a sharp knife in hot water and wipe dry. Dip and dry between each slice for perfect slices.Note: Baking the crust is optional here, but it does hold together better if baked.