To make the barbecue sauce, warm the oil in a large saucepan over medium heat. Add the onion and sauté until softened, about 3 minutes. Add the garlic and sauté an additional minute. Add the ketchup, Worcestershire sauce, apple cider vinegar, brown sugar, dry mustard, chili powder, cumin and about 1 teaspoon of salt. Bring to a simmer and then reduce to low. Be sure to stir occasionally to keep from burning.
Once the sauce has thickened, after about 10 minutes, stir in the hot pepper sauce of your choosing.
To make the dry rub, add the spices and salt to a small bowl. Stir to combine.
Preheat the broiler. Cut the ribs into 3-4 rib segments. Place the ribs on a sheetpan and sprinkle both sides with the dry rub. Place the ribs under the broiler for about 4-5 minutes. Flip the ribs and continue broiling for 5 more minutes.
Transfer the ribs to a slow cooker, add the barbecue sauce, and evenly coat the ribs in sauce. Cover and cook the ribs on the low for 5-6 hours. The ribs should be very tender.
If you'd like to separate some of the fat from the pan, after the ribs are cooked pour the remaining sauce into a small saucepan and let it stand for a few minutes. This will allow it to separate. Use a spoon to skim the fat off of the top. Bring the remaining sauce to a rapid boil for 3-4 minutes to reduce and thicken.