Lightly pound the thick end of each chicken breast on a cutting board until the meat is an even thickness from end to end.
Brine the Chicken: In a medium bowl, stir water and kosher salt until the salt dissolves. Stir in garlic powder. Add the chicken, cover, and refrigerate for 1 hour.
Make the Rub: In a small bowl, mix together the onion powder, paprika, thyme, and black pepper. Set aside.
Preheat the air fryer to 375°F (190°C).
Remove the chicken from the brine, discard the liquid, and pat dry with paper towels.
Brush olive oil evenly over both sides of the chicken and generously coat both sides with the rub.
Place chicken in the air fryer basket. Cook at 375°F (190°C) for 10–12 minutes, flipping halfway through.
Use a meat thermometer in the thickest part of the breast. If it reads 165°F (74°C), it’s ready. If not, cook for 2–3 more minutes. Let the chicken rest for at least 5 minutes before slicing so the juices can redistribute, keeping the meat moist and flavorful.
Notes
Brine for Best Results: Even a short 1-hour brine will make a noticeable difference in juiciness.
Size Matters: Small to medium breasts (5–6 oz.) take about 12 minutes. Larger pieces may need an extra 2–4 minutes.
Rest Before Slicing: Let the chicken sit for 5 minutes after cooking to retain juices.
Check Your Model: Air fryer cook times can vary, so test for doneness before serving.