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 glaze reduces by about half and thickens, approximately 10 to 12 minutes. Set aside to cool slightly.
02 - Pat the chicken breasts dry with paper towels and brush evenly with olive oil. Season lightly with additional salt and pepper.
03 - Reserve 1/3 cup of the prepared glaze for basting during grilling. Place the remaining glaze and the seasoned chicken breasts into a large resealable bag or shallow dish. Marinate in the refrigerator for at least 30 minutes, or up to 2 hours for deeper flavor penetration.
04 - Preheat the grill 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 chicken breasts onto the hot grill and cook for 5 to 7 minutes per side, basting frequently with the reserved glaze, until the internal temperature reaches 165°F and the exterior is nicely caramelized.
06 - Transfer the grilled chicken to a cutting board and let it rest for 5 minutes before slicing. Drizzle with any remaining glaze if desired and serve immediately.