Preheat your oven to 250°F and place a wire rack on a rimmed baking sheet. Spray the rack with cooking spray.
Pat the chicken wings dry with paper towels until they're as dry as possible.
In a large zip-top bag, combine the baking powder and salt. Add the wings and shake until well coated.
Place wings skin-side up on the prepared rack. Bake for 30 minutes at 250°F on the lower-middle oven rack.
After 30 minutes, increase the oven temperature to 425°F. Move the wings to the upper-middle rack and bake for 40-50 minutes, rotating the sheet halfway through baking.
Remove from oven, let rest 5 minutes, and toss in your favorite sauce or serve plain with dip.