01 - Preheat oven to 300°F.
02 - Pat beef chuck roast dry with paper towels. In a small bowl, combine kosher salt, black pepper, smoked paprika, garlic powder, and onion powder. Rub spice mixture evenly over all surfaces of the beef.
03 - Heat olive oil in a large Dutch oven over medium-high heat. Sear beef on all sides until deeply browned, approximately 2-3 minutes per side.
04 - Pour beef broth, apple cider vinegar, and Worcestershire sauce into the pot around the beef. Cover tightly with lid or aluminum foil.
05 - Transfer Dutch oven to preheated oven. Roast for 4 to 4.5 hours until beef is fork-tender and shreds effortlessly.
06 - While beef roasts, combine ketchup, apple cider vinegar, brown sugar, molasses, Worcestershire sauce, smoked paprika, garlic powder, onion powder, black pepper, and cayenne pepper in a saucepan. Simmer over low heat for 10-15 minutes, stirring occasionally. Adjust seasoning to taste.
07 - Remove cooked beef from oven and transfer to a large bowl. Skim excess fat from cooking liquid. Shred beef using two forks. Add approximately 1/2 cup of cooking liquid to shredded beef for moisture. Mix in half of the prepared BBQ sauce, reserving remainder for serving.
08 - Pile shredded beef onto sandwich buns. Top with additional BBQ sauce, red onion, lettuce, and pickles as desired. Serve immediately.