Bring 2 cups water to a boil. Add brine mix and stir until dissolved. Pour over ice in a flat bottomed resealable container. Add chicken, then add additional water until chicken is submerged. Brine for at least 5 hours or up to 12 hours.
Remove chicken from brine and rinse with cold water. Pat dry on a paper towel, then pound down the thicker end of the chicken breast until they are even thickness across.
Rub the chicken with 1 tsp olive oil until evenly coated. Season with salt, pepper, chili powder, and Oh My Spice! seasoning.
Pre-heat the air fryer to 400°F.
Air fry the chicken at 400°F for 11-12 minutes, or until chicken reaches 160° in the thickest part of the chicken, flipping the chicken halfway through. Set aside to rest for about 3-5 mintes before slicing.