For the POM barbecue sauce: In a medium bowl, combine the ketchup, brown sugar, apple cider vinegar, smoked paprika, liquid smoke, POM Wonderful Pomegranate Cherry 100% Juice, mustard powder, garlic powder, and onion powder. Set aside half the mixture to use another time.
For the smoky coffee rub: In a small bowl, mix the garlic powder, smoked paprika, instant coffee, brown sugar, pepper, salt, and onion powder. Coat the chicken generously with the mixture.
Heat a grill or grill pan over medium-high heat and coat with a thin layer of oil.
Place the chicken on the grill or pan in a single layer and don’t overcrowd – do this in batches as needed. Grill until the edges of the chicken become white and opaque, then flip. The chicken should release easily from the pan. Brush the top side of the chicken with the POM barbecue sauce. Once the bottom releases easily, flip it again. Brush the remaining side with the barbecue sauce. Use a meat thermometer to test if the chicken is fully cooked – it should read 165°F.