Rinse the Pork Shoulder under cold water and pat dry with paper towels. Trim any excess fat if desired.
In a small bowl, mix the Brown Sugar, Paprika, Chili Powder, Cumin, Onion Powder, Garlic Powder, Salt, Black Pepper, and Cayenne Pepper (if using).
Rub the spice mixture all over the Pork Shoulder, ensuring it is well coated.
Place the sliced Onions and minced Garlic in the bottom of the Slow Cooker.
Place the seasoned Pork Shoulder on top of the Onions and Garlic.
Pour the Barbecue Sauce, Chicken Broth, Apple Cider Vinegar, and Orange Juice over the Pork.
Cover the Slow Cooker with the lid. Cook on low for 8-10 hours (or on high for 4-6 hours) until the Pork is tender and easily shredded with a fork.
Once the Pork is done, remove it from the Slow Cooker and place it on a large plate or cutting board. Use two forks to shred the Pork into bite-sized pieces.
Return the shredded Pork to the Slow Cooker and mix it with the Juices and Onions.
Serve the Pulled Pork on buns, piled with your favorite slaw. Pour a glass of 2018 Stardust Cabernet Sauvignon, and enjoy!