Preheat oven to 375 degrees F. Spray 9" pie dish with cooking spray and set aside.
In a large bowl, combine the two flours, baking powder, salt and whisk. Add cubed butter and work it in with a fork and then hands until the mixture is crumbly.
Then add in maple syrup and cold water; start mixing with a spatula, then use your hands until a dough ball forms. If necessary, add a little more water or flour (one teaspoon at a time).
Sprinkle flat surface (countertop) and the dough ball with whole wheat flour. Using a rolling pin, roll out the crust until it's large enough to cover the pie dish. First, flatten the dough ball with your hands and then use the rolling pin. Dust the dough with flour while rolling, and it might help to place it on a parchment paper half way through for easier rolling and moving.
Transfer crust into the pie dish and mould to fit using your hands. Cut excess dough with kitchen scissors or knife, and make pretty edges with a fork. Poke the crust with a fork about 15 times all around and bake for 15 minutes.
While crust is baking, in a medium bowl, add eggs, pumpkin puree, maple syrup, vanilla, pumpkin pie spice, salt and whisk really well.
Reduce oven temperature to 350 degrees F, pour pumpkin pie filling into pre-baked crust and bake pie for 55 minutes.
Remove from the oven and let pumpkin pie cool almost completely, about 2-3 hours, before slicing.
Using serrated knife, cut into 8 slices and serve with whipped cream or your favourite way.
Notes
Store: Refrigerate covered for up to 5 days.
Freeze: Tightly wrapped in plastic for up to 3 months.
Make ahead: You can bake this pie the day before. Or make the dough and filling the day before, refrigerate and bake when ready.
Custard like filling: If you like more of a custard pumpkin filling, add 1/2 cup any milk to the filling before baking. Without milk pumpkin pie has more of a pure pumpkin taste.
Don’t chill the pumpkin pie until it’s set: If you move it to the fridge too soon, it can become 'weepy' as moisture rises to the top of the pie. Though if that does happen, use a paper towel to blot it.