Adjust your oven racks to upper-middle and lower-middle positions. Preheat your oven to 250 degrees. Prepare a rimmed baking sheet with tinfoil and a rack coated in cooking spray. Set aside. In a small bowl combine baking powder, garlic powder, chicken seasoning, seasoned salt and pepper. Set aside. Wash and pat your chicken thighs dry with paper towels and place in a large re-sealable bag or bowl. Sprinkle baking powder mixture all over your thighs while they are inside the resealable bag or in your bowl. Adjust and shake the thighs around to make sure they are all lightly coated in the baking powder mixture. Place the chicken thighs on your prepared sheet. Bake for 50 minutes on the lower-middle rack. Remove your wings from lower-middle and move to upper-middle rack and turn the temperature up to 425 degrees. Bake for another 45-55 minutes and thighs are a nice golden brown color. Exact timing will depend on the size of your chicken thighs. Try to turn your baking sheet halfway through baking. Remove thighs from oven and let stand for at least 5 minutes before serving. Serve and enjoy!
Source : allrecipes.com