Lightly grease the inside of your crockpot with olive oil.Or use a crockpot bag and spray oil all over it
Place the raw chicken breasts in an even layer at the bottom of the slow cooker.
In a small bowl, mix the barbecue sauce, brown sugar, garlic powder, dried minced garlic, crushed red pepper flakes, and black pepper until well combined.
Pour the sauce mixture evenly over the chicken, making sure each piece is fully coated.
Cover and cook on LOW for 5–6 hours or HIGH for 2½–3 hours, until the chicken is tender and fully cooked