Prepare the Brisket: Pat the brisket dry with paper towels.
In a small bowl, mix the paprika, chili powder, garlic powder, onion powder, cumin, salt, black pepper, and cayenne (if using).
Rub the spice mixture all over the brisket, ensuring it's evenly coated. Place the coated brisket in the crockpot. For extra flavor, sear the brisket in a hot pan with oil for 2–3 minutes per side before placing it in the slow cooker.
Make the Sauce: In a bowl, whisk together the BBQ sauce, beef broth, apple cider vinegar, Worcestershire sauce, brown sugar, and mustard.
Slow Cook: Pour the sauce over the brisket in the slow cooker.
Cover and cook on LOW for 8–10 hours or HIGH for 5–6 hours until the brisket is very tender and easily falls apart.
Shred the Brisket: Remove the brisket from the slow cooker and place it on a cutting board or a large dish.
Use two forks to shred the brisket into bite-sized pieces.
Mix & Serve: Return the shredded brisket to the slow cooker and mix it with the sauce.
Let it sit for 10–15 minutes on the "Keep Warm" setting to absorb the flavors.
Assemble: Toast buns (optional), then layer the shredded brisket, cheddar cheese, and coleslaw. Serve warm.