In a small mixing bowl, combine the smoked paprika, black pepper, garlic salt, onion powder, and Cajun seasoning. Mix well to create a flavorful seasoning blend.
Generously coat both sides of the beef roast with the seasoning mixture, ensuring even coverage for maximum flavor. Place the seasoned roast into the slow cooker.
Pour one cup of BBQ sauce over the beef, covering it as evenly as possible. Secure the lid and cook on low for 6-8 hours, allowing the meat to become tender and fall apart effortlessly with a fork.
Once fully cooked, shred the beef directly in the slow cooker using two forks. Add the remaining cup of BBQ sauce, stirring thoroughly to coat every strand of the pulled beef in its rich, smoky sauce.
Serve the tender, saucy pulled beef on fresh buns, adding slices of cheddar cheese if desired for an extra layer of richness. Enjoy immediately while warm!