Step 1

Spray a 6-quart slow cooker with cooking spray.

Step 2

Trim excess fat from brisket, leaving a ¼-inch to ½-inch-thick layer. Pat dry with a paper towel; rub with salt and black pepper on both sides.

Step 3

Coat a 12-14-inch cast iron skillet with oil, and heat over medium-high heat. Reduce heat to medium. Add brisket; cook until browned, 3-5 minutes per side (adjust heat as needed). Place brisket in slow cooker (do not clean out the skillet).

Step 4

In a small bowl, combine brown sugar, chili powder, paprika, garlic powder, and red pepper; sprinkle on the brisket, turning to coat. Turn brisket fat side up. Pour bbq sauce and Worcestershire sauce around the sides of the brisket.

Step 5

In the same cast iron skillet, cook onion over medium-high heat, just until browned (about 1-2 minutes per side). Transfer onion to the slow cooker. Add beer to the skillet and cook over low heat for about 1-2 minutes, scraping the browned bits from the bottom of the pan. Pour the beer and other drippings from the skillet into the slow cooker.

Step 6

Cover and cook until tender, about 3-4 hours on HIGH or 6-8 hours on LOW. The meat should reach an internal temperature of about 195°F (just remember that the temperature will continue to rise as it rests, so you can pull it out of the slow cooker once it reaches about 185°F).

Step 7

Place the brisket on a cutting board; let stand for 15 minutes. Slice brisket against the grain. Taste and season with additional salt and pepper, if necessary. Serve on sandwich rolls with extra bbq sauce, the onions from the pot, and sliced pickles if desired.