Preheat the oven to 425°F.
To prepare the crust: In a medium-size bowl, stir together the spelt flour, salt, and Stevia. In a small bowl, stir together the whey mixture and oil. Add the wet ingredients to the dry, mixing well. Form the crust mixture into a ball; press onto the bottom of a 9-inch pie plate and 1 inch up the sides.
To prepare the filling: In a large bowl, blend together the pumpkin, 2 tablespoons of the whey mixture, the spices, and the salt. Add the remaining filling ingredients. Mix gently just until all the ingredients are thoroughly combined.
Pour the filling into the pie crust.
Bake for 15 minutes; lower the heat to 350°F and bake for an additional 40 minutes, or until a knife inserted into the center comes out clean.
Check the pie after about 25 minutes.
If the outside gets too brown, cover the edges with foil.