Add the graham cracker crumbs and melted butter to the bottom of a 9x13-inch baking dish. Gently mix well, then press into the bottom of the dish. Refrigerate the crust for 15 minutes.
Spread the no-bake cheesecake filling evenly over the chilled graham cracker crust.
Whisk the instant vanilla pudding and milk together in a medium mixing bowl until thickened. Fold in the pumpkin puree and pumpkin pie spice.
Carefully spread the pumpkin pudding mixture on top of the cheesecake layer.
Spread whipped topping over the pumpkin layer and garnish with a dusting of pumpkin pie spice. Chill in the refrigerator for at least 4 hours before serving.
Notes
For best results, ensure the dessert chills for the full 4 hours so the layers can properly set before slicing.