Remove membrane from the back of ribs. Cut the rack in half.
In a small mixing bowl, whisk together brown sugar, cinnamon, chili pepper, salt, pepper and garlic powder. Sprinkle rub over ribs and rub into the meat.
Place ribs in 5 to 6 quart slow cooker. They will overlap slightly.
Whisk barbecue sauce with apple cider vinegar and pour over ribs. Brush all over meat.
Cook ribs on HIGH setting for 4 hours or LOW for 6 hours.
Preheat oven to 420 degrees F. Remove ribs from slow cooker and place on aluminum foil lined large baking sheet. Brush with more barbecue sauce. Place in oven on middle rack and bake until the the sauce caramelizes, about 10 minutes. Keep an eye on them.
Serve with a side of a coleslaw and extra napkins.