01 - Rub the beef chuck roast thoroughly with kosher salt and black pepper on all sides.
02 - Heat olive oil in a large skillet over medium-high heat. Sear the beef on all sides until deeply browned, approximately 3 to 4 minutes per side.
03 - Move the seared beef to the slow cooker insert.
04 - Whisk together the barbecue sauce, beef broth, apple cider vinegar, brown sugar, Worcestershire sauce, smoked paprika, garlic powder, onion powder, and cayenne pepper in a bowl until smooth.
05 - Pour the prepared sauce mixture evenly over the beef in the slow cooker.
06 - Cover and cook on low setting for 8 hours or on high setting for 4 hours until the beef becomes fork-tender and shreds effortlessly.
07 - Remove the cooked beef from the slow cooker and shred using two forks. Skim any excess fat from the sauce if preferred, then return the shredded beef to the sauce and toss to coat thoroughly.
08 - Brush the inside of each bun with melted butter and toast in a skillet or under the broiler until golden brown and crisp.
09 - Heap the sauced pulled beef generously onto the toasted buns. Top with coleslaw if desired and serve immediately.