Prepare rub in a small bowl and set aside.nDrizzle olive oil on chicken and generously season both sides with the rub.nGrill over direct heat until cooked through, flipping once or twice.nLet chicken cool for a few minutes and then shred the chicken.nToss with barbecue sauce.nSauté diced onion in olive oil until soft and translucent.nStir in chili powder, garlic powder and cayenne pepper.nPour in root beer and stir to combine.nStir in ketchup, lemon juice and molasses.nBring sauce to a boil, reduce heat and simmer for 15 minutes or until sauce has thickened.nTop toasted buns with chicken mixture and coleslaw if you like.