Prep the slow cooker: Add sliced onion and minced garlic to the bottom.
This creates flavor and a little moisture buffer.
Season the chicken: Pat the chicken dry. Sprinkle on salt, pepper, smoked paprika, and chili powder. Place the chicken on top of the onions.
Mix the sauce: In a bowl, combine BBQ sauce, broth, apple cider vinegar, and brown sugar or honey (if using).
Stir until smooth and pour over the chicken.
Cook low and slow: Cover and cook on Low for 4–6 hours (best for tender results) or High for 2.5–3.5 hours. The chicken should shred easily with two forks.
Shred the chicken: Transfer chicken to a large bowl and shred with forks. Skim excess fat from the cooker if needed.
Thicken and adjust: Return shredded chicken to the slow cooker and stir to coat.
Taste and adjust seasoning—add a splash of vinegar for tang, more sauce for sweetness, or a pinch of salt.
Toast the buns: Optional but worth it. Spread butter on the cut sides and toast in a skillet over medium heat until golden. This keeps them from getting soggy.
Assemble: Pile warm BBQ chicken onto buns.
Top with coleslaw and pickles if you like. Serve immediately.