Make the cashew cream. Drain and rinse the soaked cashews. In a high-speed blender, blend the drained cashews and the water on high speed until very smooth, 2 to 3 minutes. Set aside.
Preheat the oven to 350°F.
Make the crust. In a food processor, combine the pecans, oat flour, brown sugar, melted butter, cinnamon, and salt. Pulse until the mixture is finely ground and sticks together well when pressed between your fingers.
Tip the pecan mixture into a 10-inch pie pan and, using the flat bottom of a glass, press it evenly and firmly onto the bottom and up the sides to form the crust.
Bake for 12 minutes, or until the crust looks slightly cooked but not brown. Set aside.
Make the filing. In a large bowl, combine the pumpkin puree, Cashew Cream, eggs, brown sugar, cinnamon, ginger, nutmeg, cloves, allspice, and salt. Whisk until smooth.
Pour the filling into the crust and bake until the center of the pie is set (a butter knife should come out clean), 30 to 40 minutes. Transfer to a rack and let cool completely. Store, covered, in the fridge for up to 3 days.
*You can skip soaking the cashews if using a Vitamix Blender.