Preheat oven to 375° 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.
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.