Remove ribs from the fridge and let come to room temp while you blend your spice rub. Rinse and pat dry, then place on a large piece of aluminum foil (wide enough to loosely wrap them completely) set on top of a baking sheet.
Rub 1-2 tbsp on each side on the ribs and let rest while the oven comes to temp (see temperature options below.) Extra rub will keep in a sealed container for a month.
Fold over foil to make a canoe shape and pour over apple cider vinegar. Crimp the foil together so the steam can collect at the top of the foil while they roast. You don't want any holes or openings in the foil.
Set oven to 400 degrees while blending rub.
Roast baby back ribs for 50 minutes and spareribs for 80 minutes.
Open up foil pouch to release steam (don't get your face too close) and thickly spread on the BBQ sauce (on both sides if possible.)
Roast again for an additional 10-15 minutes without resealing the foil pouch, or until a knife slides into the thickest part of the meat easily. Let rest for 10 min, and then break down into individual ribs to serve (with extra sauce if needed.)
Follow all the same directions as for high heat, but just adjust temperature and times. Set oven to 325 while blending rub.
Roast the baby backs for 75 min in foil and then 30 minutes with sauce (re-seal the foil this time), or the spareribs for 2 hours in foil and then 30 minutes with sauce (re-seal foil.) If you want a darker color to the ribs, open up the foil pouches for the last 15 minutes of cooking. You can also give the ribs a quick sear at the end on a very hot cast iron skillet or grill pan for just a minute or 2 each side.