Season the Brisket:
Mix together paprika, garlic powder, onion powder, cayenne (if using), salt, and pepper. Rub generously all over the brisket.
Sear (Optional but Recommended):
Heat olive oil in a skillet over medium-high heat. Sear brisket on both sides until browned (about 4–5 minutes per side). Transfer to slow cooker.
Make the BBQ Sauce:
In a bowl, whisk together all BBQ sauce ingredients. Taste and adjust seasoning as needed.
Slow Cook:
Pour half of the BBQ sauce over the brisket. Cover and cook on low for 8 hours or high for 5 hours, until the meat is fork-tender.
Shred or Slice:
Remove brisket and let rest for 10 minutes. Slice or shred. Skim fat from juices if desired.
Serve:
Return meat to the slow cooker with remaining BBQ sauce to warm through. Serve on sandwich buns, with coleslaw, or alongside mashed potatoes or cornbread.