Preheat oven to 375 degrees F.
Spray an 8" square baking dish with cooking spray
In a medium bowl, mix flour, coconut flakes, sugar, baking powder, baking soda, & salt.
Melt butter and then set aside to cool for 5 minutes; then place in the refrigerator for 4 minutes to ensure that it is cool enough to add to the flour mixture.
Add cooled butter to flour mixture and press with a large, sturdy fork until well blended and the mixture resembles coarse crumbs.
Reserve one cup of the flour mixture and set aside.
Press the remaining flour mixture into the bottom of the glass baking dish to form the bottom crust.
In a separate bowl, combine the drained crushed pineapple, sugar, and cornstarch.
Pour mixture over the pressed crust and spread evenly.
Sprinkle remaining 1 cup of flour mixture on top of the pineapple filling.
Bake bars on center rack of oven for 30 minutes or until topping is golden. My oven took 35 minutes.
Cool bars completely before cutting.