Preheat your oven to 225F.
Place ribs, meat side up, on jelly roll pan in the oven.
We're using a jelly roll pan just in case any juices escape your packet - it will contain the mess. Cook the ribs in the packet for about 2.5 hours.
Has it been 2.5 hours already? Pull your ribs out of the oven and carefully (steam!) open your packet of foil. At this point you can sort of wrap the foil around the pan, or trim it, or just smoosh it up so it's not in the way.
Baste the top and bottom of the ribs (careful on the bottom!) with the sauce you made earlier and return to the oven meat side up.
In about 15 minutes, turn once and baste with sauce.
In another 15 minutes, turn back over (we should be meat side up again), baste and return to the oven.
Continue to baste the top every 15 minutes (or so, you don't have to set a timer to it or anything) until the tip of a small knife slips easily in and out of the meat.
Serve with remaining sauce on the side.