Toast for 7-10 minutes on middle shelf, or until the smell of nuts fills the kitchen.
Combine oats, flour, remaining pecans, 1/2 teaspoon cinnamon, and a pinch of salt in a food processor.
Pulse until mixture becomes a coarse meal. Whisk together applesauce and 3 tablespoons maple syrup.
Mix into dry ingredients to form a soft dough.
Press mixture into pie plate. Crimp edges. Bake for 10 minutes, and set aside to cool.
Using a whisk, dissolve the cornstarch in the milk.
Add pumpkin, 1/2 cup maple syrup, salt and spices.
Blend until smooth.
Pour filling into crust, and smooth the top.
Bake for about 35 minutes, or until the crust is lightly browned and the outside inch of the filling is set. Don't worry if the center is still soft; it firms up as the pie cools. Transfer pie to a wire the rack.
Cool to room temperature, and then chill until set, about 3 hours. Serve chilled or at room temperature.