Preheat the oven to 450 degrees F (230 degrees C). Grease a 9-inch pie pan and line with gingersnap cookies (should be 12 to 14 cookies).
Whisk pumpkin, almond milk, sugar, egg, molasses, cornstarch, cinnamon, ginger, nutmeg, and salt together in a bowl; carefully pour over cookies.
Bake in the preheated oven for 15 minutes. Turn heat down to 350 degrees F (175 degrees C) and continue to bake until set, 30 to 35 minutes. Let cool to room temperature before cutting.