01 - Rub the beef chuck roast generously with kosher salt and freshly ground black pepper, coating all surfaces evenly.
02 - Heat olive oil in a large skillet over medium-high heat. Brown the beef on all sides for 3-4 minutes per side until a deep crust forms.
03 - Transfer the seared beef to the slow cooker insert.
04 - Whisk together barbecue sauce, beef broth, apple cider vinegar, brown sugar, Worcestershire sauce, smoked paprika, garlic powder, onion powder, and cayenne pepper 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 high setting for 4 hours until the meat pulls apart effortlessly with a fork.
07 - Remove the cooked beef from the slow cooker. Using two forks, shred the meat into bite-sized pieces. Skim any excess fat from the cooking liquid, then return the shredded beef and toss to coat thoroughly.
08 - Brush the cut sides of sandwich buns with melted butter and toast in a skillet or under the broiler until golden brown, about 2-3 minutes.
09 - Mound the saucy pulled beef onto the toasted buns. Top with coleslaw if desired and serve immediately while hot.