01 - In a small saucepan, combine the Coca Cola, ketchup, soy sauce, brown sugar, apple cider vinegar, garlic powder, smoked paprika, black pepper, and salt. Bring to a simmer over medium heat and cook, stirring occasionally, until the mixture reduces by about half and thickens to a glossy consistency, approximately 10 to 12 minutes. Set aside to cool slightly.
02 - Pat the chicken breasts dry with paper towels and brush both sides with olive oil. Season lightly with additional salt and pepper.
03 - Reserve 1/3 cup of the prepared glaze for basting during grilling. Combine the remaining glaze with the chicken breasts in a large resealable plastic bag or shallow dish. Refrigerate and marinate for at least 30 minutes, or up to 2 hours for more pronounced flavor.
04 - Preheat an outdoor grill or grill pan to medium-high heat, targeting approximately 400°F. Oil the grates thoroughly to prevent the chicken from sticking.
05 - Remove the chicken from the marinade and discard the used marinade. Place the breasts onto the hot grill and cook for 5 to 7 minutes per side, basting frequently with the reserved glaze, until the internal temperature registers 165°F on a meat thermometer and the exterior is deeply caramelized.
06 - Transfer the chicken to a cutting board and allow it to rest for 5 minutes so the juices redistribute. Slice and drizzle with any remaining glaze before serving.