Preheat the oven to 350 degrees F (175 degrees C). Spray a baking sheet with cooking spray.
Heat a cast-iron skillet over high heat until it is smoking hot, about 5 minutes.
While the skillet is heating, mix together paprika, cayenne, cumin, thyme, onion powder, white pepper, and salt in a small bowl. Spray chicken breasts on both sides with cooking spray, then coat evenly with spice mixture.
Place chicken in the hot pan and cook for 1 minute. Turn, and cook for 1 minute on other side. Transfer the chicken to the prepared baking sheet.
Bake in the preheated oven until chicken is no longer pink in the center and the juices run clear about 5 minutes.