Directions

1. Mix brown sugar, chili powder, paprika, salt, pepper, mustard powder, onion powder, and garlic powder for dry rub together in a small bowl.
2. Mix beef broth, liquid smoke, and Worcestershire sauce for cooking liquid in a separate bowl.
3. Place onions and carrots in a slow cooker. Pour cooking liquid over top and set to temperature High to let it warm up.
4. Meanwhile, rinse brisket under cold water. Pat it dry, then season all over with the dry rub. Place brisket in the slow cooker on top of the onions and carrots, with the fatty side facing up. The cooking liquid should reach just to the bottom of the brisket; if not, add a little water.
5. Cover and cook on Low for 8 hours. Turn the slow cooker off and transfer brisket to a foil-lined sheet pan. Trim some of the fat if desired.
6. Place barbecue sauce in a bowl. Ladle 1/4 cup hot cooking liquid from the slow cooker into the bowl and mix it with the barbecue sauce. Baste the fatty side of the brisket with this mixture.
7. Preheat the oven's broiler.
8. Place the brisket in the preheated oven so there are 6 inches between the top of the brisket and the burner. Broil until the fatty edges start to crisp up, 2 to 4 minutes; watch closely so it doesn't burn.
9. Remove from the oven and let rest for 10 minutes. Slice brisket thinly and against the grain.
10. Remove vegetables from the slow cooker with a slotted spoon, and serve alongside the brisket.