Defrost wings completely before using.
Pat wings dry with paper towels to remove excess moisture. And set aside.
Prepare your oven: placing one oven rack on the lowest height setting and one rack near the top.
Preheat the oven to 250F
Place wings in a large zip top bag. Add the baking powder and salt to the bag, and shake to evenly coat wings. Make sure there are no clumps
Place a wire cooling rack over/inside a baking sheet, and spray cooling rack with cooking spray or brush with oil.
Place the coated wings on the rack, leaving a little space between each wing, but you don't need a ton of room.
Spray wings with cooking spray or brush lightly with oil.
Bake on the lower oven rack for 30 minutes.
After 30 minutes, move tray to the higher rack, and turn the oven up to 425F / 220C.
Bake an additional 25-35 minutes until skin is golden brown and crispy, and internal temperature reaches 165 degrees.
Bake longer if desired crispiness is not reached.
Remove from oven.