Preheat your oven to 350°F (175°C). Lightly grease a 9-inch pie dish or a similar-sized baking dish.
In a large bowl, combine the canned pumpkin, evaporated milk, eggs, and egg whites. Whisk until smooth and well blended.
Add the granulated sugar, cinnamon, allspice, ginger, and salt to the pumpkin mixture. Stir well to evenly distribute the spices.
Fold in the graham cracker or vanilla wafer crumbs. These crumbs help add a subtle texture and slightly thicken the filling, even without a crust.
Pour the mixture into your prepared baking dish, smoothing the top with a spatula.
Bake in the preheated oven for 50 to 60 minutes, or until the center is set but still slightly jiggly. A toothpick inserted near the center should come out mostly clean.
Allow the pie to cool completely on a wire rack, then refrigerate for at least 2 hours to help it firm up further.
Before serving, top with whipped cream if desired for a rich, creamy finish.
Enjoy!