Preheat the Oven: Preheat your oven to 325°F (163°C).
Prepare the Ribs: Remove the membrane from the back of the rack of ribs and pat them dry with paper towels.
Make the Spice Rub: In a small bowl, combine the brown sugar, salt, granulated garlic, granulated onion, ground mustard powder, paprika, and chili powder.
Season the Ribs: Rub the spice mixture all over the ribs, covering them evenly on both sides.
Cook the Ribs: Place the seasoned ribs on a foil-lined baking sheet, bone side down. Cover the ribs tightly with aluminum foil and bake in the preheated oven for 1 1/2 hours.
Prepare the BBQ Sauce: While the ribs are cooking, make the BBQ sauce. In a saucepan, combine the ketchup, apple cider vinegar, Worcestershire sauce, brown sugar, granulated garlic, granulated onion, water, and salt to taste. Bring the mixture to a simmer over medium heat, stirring occasionally, and let it cook for about 10 minutes until slightly thickened.
Finish cooking the Ribs: After 1 1/2 hours, remove the foil from the ribs and increase the oven temperature to 400°F (204°C). Brush the ribs generously with the prepared BBQ sauce on both sides.
Broil the Ribs: Return the ribs to the oven and cook at 400 for about 5-10 minutes, or until the sauce is caramelized and bubbling.
Serve: Once the ribs are cooked to your liking and the sauce is caramelized, remove them from the oven and let them rest for a few minutes before slicing and serving. Serve any extra BBQ sauce on the side for dipping.
