Preheat oven to 375 degrees. In a mixing bowl, combine all the dry ingredients. Heat a large ovenproof skillet over medium heat. Add almost all of the 2 tablespoons olive oil to the skillet. Brush both sides of chicken breasts with remaining oil.
Generously rub chicken with the cocoa-chili rub until evenly coated on all sides. Place chicken into skillet and sear on both sides. Remove skillet from heat and bake in the oven for approximately 12 minutes or until chicken is cooked through.