Season the beef ribs with salt and pepper on all sides.
Place the chopped onion and minced garlic in the bottom of the slow cooker.
In a separate bowl, whisk together the barbecue sauce, brown sugar, apple cider vinegar, Worcestershire sauce, Dijon mustard, smoked paprika, and chili powder.
Pour half of the sauce mixture over the onions and garlic in the slow cooker.
Place the seasoned beef ribs on top of the sauce in a single layer.
Pour the remaining sauce mixture over the beef ribs, ensuring they are coated evenly.
Cover the slow cooker and cook on low heat for 6-8 hours, or until the beef ribs are tender and easily pull away from the bone.
Once cooked, carefully remove the beef ribs from the slow cooker and place them on a baking sheet lined with aluminum foil.
Preheat your oven’s broiler on high heat.
Brush the beef ribs with some of the sauce from the slow cooker, reserving the remaining sauce.
Place the baking sheet with the beef ribs under the broiler for 3-5 minutes, or until the sauce becomes slightly caramelized and sticky. Keep a close eye on them to prevent burning.
Remove the beef ribs from the oven and let them rest for a few minutes.
Serve the barbecued beef ribs hot, drizzled with additional sauce from the slow cooker.
These ribs pair well with classic soul food sides like cornbread, mac and cheese, or collard greens.
Enjoy the tender, flavorful, and fall-off-the-bone barbecued beef ribs straight from your slow cooker!