Mix all the spice rub ingredients and season both sides of the ribs with it generously. Place the ribs, meat-side up, into a large roasting pan or rimmed baking sheet lined with foil. Cut in half if necessary.
Cover the pan or baking sheet tightly with aluminum foil, and then bake until the meat falls easily from the bones, 2.5 to 3 hours. Check the ribs after 2 hours to see how they are progressing and add a little bit of water if it looks dry. The ribs are done when the meat is cooked through and tender.
Barbeque sauce
Heat the olive oil (1 tbsp) in a saucepan over medium heat.
Add the onions (1/4 cup) and cook until soft and translucent, 5-8 minutes. Stir in the cumin (1/2 tsp) and cook for an additional 30 seconds.
Add the ketchup (1/2 cup), hot sauce (1 tbsp), brown sugar (1 tbsp), and apple cider vinegar (1 tbsp). Stir to combine, season with salt then cook for 2 minutes or until it thickens. Store in a clean jar.
To finish
Increase oven temperature to 500°F/260°C. Remove ribs from the oven and remove the foil lid.
Spread some bbq sauce evenly on the top of the ribs.