In a small bowl, whisk together the brown sugar, paprika, garlic powder, cumin, chili powder, salt, and pepper. Cut the pork into 6-8 smaller pieces, and rub the spice mixture over all surfaces of the meat.

To make the sauce, whisk together the barbecue sauce, beef broth, and apple cider vinegar in a small bowl or measuring cup.

Add the pork pieces to the slow cooker. Pour the sauce over the top of the pork. Cover and cook on low heat for 6-8 hours, until the pork is tender and easy to shred.

Shred the pork pieces, discarding any chunks of fat, and place on a rimmed baking sheet. Drizzle 1 cup of the sauce over the top of the pork. Broil 5-10 minutes, or until the pork is just slightly crispy and browned. Serve hot.