Separate the point from the flat. Place a large brisket on a cutting board, fat cap side down. Use a sharp knife to first trim away the excess fat from the sides of the brisket. Then, cut through the fat across the brisket in a sort of sloping horizontal direction following the fat line to separate the "flat" of the brisket from the "point". You should be able to cut through fat the whole way across the brisket. You can use the flat of the brisket to make my oven-roasted BBQ beef brisket or smoke it. Trim the fat from both sides of the point cut of the brisket leaving only about ¼-inch of the fat cap.
Preheat smoker to 225°F to 250°F with hickory or oak wood chips or whatever is your favorite wood for smoking brisket.
Combine salt, pepper, and garlic powder in a small bowl. Season the brisket all over with the beef rub. Pour the beef stock or apple cider vinegar mixture into a clean spray bottle and set aside.
Rub the brisket all over with the salt, pepper, and garlic powder mixture. See notes for adjustments needed if you are smoking both the point and the flat.
Place the seasoned meat on the smoker, close the lid, and smoke for 6-8 hours until the internal temperature of the brisket reaches 165 degrees F when tested with a digital meat thermometer. Check the brisket once every hour to spritz it with the beef stock.
Wrap the brisket in peach butcher paper or aluminum foil and place it back in the smoker for another 2-3 hours until it reaches 195 degrees F.
Remove the brisket from the smoker and unwrap it on a large cutting board. Transfer any juices from the peach paper to a large aluminum pan. Slice the brisket into evenly sized cubes, about 1½-inches each. Add them to the foil pan with any reserved juices.
Add BBQ sauce, brown sugar, honey, and reserved rub to the pan and toss the meat to evenly coat the pieces. Return to the smoker, close the lid, and smoke for another 1-2 hours until the sauce has caramelized and the meat is practically falling apart. The temperature should be between 190 and 205 degrees F.
Serve with extra BBQ sauce and sliced white bread.