Combine the brown sugar, paprika, salt, black pepper, garlic powder, onion powder, cayenne pepper, and mustard powder in a small bowl.

Rub the spice mixture all over the pork shoulder until well-coated. (For deeper flavor, marinate overnight in the fridge.)

Place the pork shoulder into the slow cooker.

Pour the apple cider vinegar, Worcestershire sauce, and chicken broth around the pork in the slow cooker.

Cover and cook on low for 8-10 hours or on high for 4-6 hours, until the pork is tender and easily shreds with a fork.

Once the pork is cooked, remove the bone if present.

Remove most of the liquid from the slow cooker, leaving the pork inside. Use a ladle or large spoon to transfer the liquid to a bowl. Reserve the liquid in case you need to add some back in later.

Shred the pork directly in the slow cooker using two forks. If the pork seems too dry after shredding, add some of the reserved liquid back in until it reaches the desired consistency.

Stir in the BBQ sauce until the pork is evenly coated.

Serve the pulled pork on buns with extra BBQ sauce and your favorite sides.