Mix brown sugar, paprika, garlic powder together.
Add onion powder, salt, and black pepper.
Rub spice mixture all over beef roast.
Heat Dutch oven over medium-high heat.
Sear beef on all sides until browned.
Combine broth, barbecue sauce, and Worcestershire sauce.
Add vinegar to the liquid mixture.
Pour sauce over seared beef roast.
Cover and cook at 325°F for 3 hours.
Remove beef when internal temperature reaches 190°F.
Let meat rest for 15 minutes.
Shred beef using two large forks.
Mix shredded beef with cooking juices.
Serve on toasted brioche buns immediately.