Preheat barbecue grill to 350 F for indirect heating.
Place the breast in a flat bowl or pan and pour cola over the breast, marinate for minimum of 1 hour to maximum of 2 hours, turning breast over frequently. Remove it from marinade, which you discard, and drain slightly.
Make a reduction sauce by combining the apple cider and maple syrup in a saucepan and cooking over medium-high heat until the liquid is reduced by half. About 20 minutes. Set aside.
On direct heat side of the grill sear the breast just until it has grill marks on each side, about 2 minutes maximum. Remove and place in the center of a large piece of aluminum foil.
Pour the reserved marinade over the turkey breast and fold the foil until all edges are securely sealed.
Place the turkey breast on the unheated side of the grill and cook for about 30 minutes or until the internal temperature is 140¢ªF. Then remove turkey from barbecue and let sit, still sealed in foil, for 10 minutes, allowing the temperature to rise to 160¢ªF.
Carefully open foil package, remove breast and slice. Placing the juice in a gravy boat to pour over the meat.