In a small bowl, whisk together brown sugar, Worcestershire sauce, pepper, dry mustard, garlic powder, liquid smoke, and salt. Rub all over brisket.
Place in a gallon-sized zipper-top plastic bag or in a dish with a cover. Refrigerate at least 30 minutes or overnight.
To make the brisket:
Transfer brisket to slow cooker. Cover and heat on HIGH for 8 to 10 hours.
Preheat broiler on HIGH. Remove brisket from slow cooker and transfer to a rimmed baking sheet or roasting pan. Brush brisket with barbecue sauce on all sides. Broil until sauce is sticky and bubbly, about 1 to 2 minutes.
Remove brisket to a cutting board and tent with foil for 10 minutes. Slice brisket thinly across the grain. Serve on grilled Texas toast or soft rolls coleslaw or red cabbage and scallions, if desired.
Beef brisket: There are two components that make up a brisket cut. The flat cut of brisket is larger, evenly shaped, and rectangular. One side will have a layer of fat. This cut is ideal for slow cooking and slicing. The point or deckle cut of brisket is more marbled and has an irregular shape that is pointed at one end. This cut is better for shredding into tacos and sandwiches. Ask your butcher for your preferred style based on your desired use. (I often opt for flat cut brisket for this recipe.)
Yield: This Slow Cooker Brisket recipe makes enough for 8 generous entree-sized servings.
Storage: Store leftovers covered in the refrigerator for up to 4 days.