01 - Place the chicken breasts in an even layer across the bottom of the slow cooker.
02 - In a small mixing bowl, whisk together the brown sugar, soy sauce, minced garlic, apple cider vinegar, smoked paprika, and black pepper until thoroughly combined and the sugar has dissolved.
03 - Pour the sauce evenly over the chicken breasts, ensuring each piece is well coated.
04 - Cover the slow cooker and cook on low for 4 hours or on high for 2 hours, until the chicken reaches an internal temperature of 165°F and is fork-tender.
05 - Remove the chicken from the slow cooker and shred using two forks or slice into portions. Spoon the accumulated sauce from the slow cooker over the top of each serving.
06 - Finish with a sprinkle of chopped fresh parsley and sliced green onions. Serve immediately while hot.