Preheat oven to 425°F. Using an oven safe grill pan, broiler pan or line a baking sheet with foil. Spray liberally with cooking spray.
Pound the thickest portion of each chicken breasts into even thickness. (This will ensure the chicken cooks evenly.)
In a small bowl, whisk together brown sugar, chili, salt, lemon pepper, garlic, paprika, thyme, onion powder and cayenne.
Drizzle chicken pieces on both sides with oil. Sprinkle both sides evenly with seasoning rubbing into the chicken pieces. Place on prepared pan.
Bake for 18-20 minutes or until juices run clear. (Internal temperature of 165°F)
Rest for 5 minutes, slice and serve.