Step 1: Pat the brisket dry with paper towels. In a small bowl, combine smoked paprika, garlic powder, onion powder, black pepper, cayenne pepper (if using), and salt. Rub this seasoning mixture generously all over the brisket.
Step 2: Heat olive oil in a large skillet or Dutch oven over medium-high heat. Sear the brisket on all sides until well browned, about 3-4 minutes per side. This step adds a crucial layer of flavor.
Step 3: Place the sliced onion and minced garlic at the bottom of your slow cooker. This creates a flavorful bed for the brisket.
Step 4: Whisk together the beef broth, BBQ sauce, apple cider vinegar, Worcestershire sauce, and liquid smoke (if using) in a medium bowl. Pour about half of this mixture over the onions and garlic in the slow cooker.
Step 5: Carefully transfer the seared brisket to the slow cooker, placing it on top of the onions and garlic. Pour the remaining BBQ sauce mixture over the brisket.
Step 6: Cover and cook on low for 8-10 hours, or on high for 4-6 hours, until the brisket is fork-tender and easily shreds apart. The exact time will depend on your slow cooker and the size of your brisket.
Step 7: Once cooked, carefully remove the brisket from the slow cooker and place it on a cutting board. Allow it to rest for 10-15 minutes, then shred it using two forks. Discard any large pieces of fat. You can skim any excess fat from the sauce in the slow cooker, then return the shredded brisket to the sauce and stir to coat. Serve warm and enjoy your incredible Slow Cooker BBQ Brisket!