In a food processor, process the walnuts and sacha inchi into a coarse meal. Add the dates and sea salt and continue to process until combined and a sticky dough-like texture is formed.
Press the mixture evenly into a springform pan sprayed with coconut oil. Set in freezer to set while you prepare the filling.
In a food processor or high-powered blender, add the soaked and drained cashews, maple syrup, lemon juice, vanilla extract, and sea salt. Blend on high until a smooth filling is formed (this may take more than a minute or two).
Spoon only 1/3 of the mixture evenly over top the crust, spreading evenly to cover. Set aside.
Add the can of pumpkin puree, cinnamon, nutmeg, and pumpkin pie spice to the remaining cashew blend, and blend on high until mixed.
Pour mixture over the top of the pie, spreading evenly. Top with walnuts.
Let sit in freezer for at least 2-3 hours before serving. Take out ~ 10 minutes before enjoying for the perfect consistency.