Preheat oven to 350° F.
Place oats in a food processor and pulse until they have the texture of a coarse flour.
Mix oat flour, flour, and cinnamon in a medium bowl.
Add cold vegan butter to flour mixture and incorporate with hands, or with a fork until coarse crumbs form.
Add water one tablespoon at a time, stirring before adding the next, until dough forms.
Pour dough mixture into a pie dish and use clean hands to press it firmly so that it covers the bottom and sides of the dish. Place in refrigerator for 20 minutes.
Bake crust 15 minutes, until slightly darker in color. Set aside.
Place pumpkin puree, avocado, maple syrup, pumpkin pie spice, vanilla extract, and almond milk in a food processor and pulse until smooth.
Pour pumpkin mixture into pie crust and bake 30 to 40 minutes more, or until filling is set in the center and brown around the edges.
Set aside to cool at room temperature until ready to serve. Cut into 12 slices and serve. Store remaining pie covered in a refrigerator for up to four days.
The Nutrition Facts box below provides estimated nutritional information for this recipe.