In a bowl, combine the paprika, chili powder, cumin, garlic powder, celery salt, salt, and pepper.
Rub mixture over brisket and place in the slow cooker. Top with bay leaves and onion.
Add broth to the slow cooker and cook on low for 8-10 hours.
Remove brisket from slow cooker and allow to rest for 5 minutes. Then slice across the grain into thin slice. Place slices on slider buns. Top with bbq sauce and coleslaw to serve. Serves 6.