We had almost these exact ribs the other weekend when we were with my parents, and they were so profoundly excellent that I had to make them again. The sauce is an adaptation of a Tyler Florence recipe, and it is really easy and worth making, despite its long list of ingredients. But if you don't want to bother, then simply use your favorite purchased sauce and the ribs will still be great because what it's all about is the long, slow cooking -- the kind of cooking that melts all the fat and tendons so that the meat pulls clean off the bones in long, succulent shards. Oh they are so good.
I made only half this rub recipe, and it seemed like enough for 2 racks. (But the leftovers are great as a seasoning for black or pinto beans!) By all means use your favorite rub recipe instead, but beware of sugar, which will predispose the ribs towards burning during their slow bake.
Heat your oven to 275° F.
Mix together the dry ingredients of the rib rub. I smashed the celery seeds and salt together with a mortar and pestle until the celery seeds looked pretty powdery (alternately, you could use celery salt and cut back on the Kosher salt a bit). Add the rest of the ingredients and stir together well.
Lay the ribs on a large, rimmed baking sheet, then rub them all over with the rib rub and pop them in the oven to bake for 3-4 hours -- the longer the better. If at any point the ribs seem to be browning excessively, turn the heat down to 250°.
Make the barbecue sauce while the ribs are baking: Fry the bacon in a pot over medium heat until it has given off most of its fat, then add the thyme, onions, and garlic and fry, stirring, until the onions are translucent and golden. Add the rest of the ingredients and bring to a simmer, then turn the heat down and simmer very gently, stirring occasionally, for about 20 minutes. Fish the bacon out before using.
Finish by barbecuing the ribs: Heat a gas grill to medium (you can add hickory chips for a nice, smoky flavor), or else let a nice wood or charcoal fire burn down to coals.
Slather the ribs with sauce and then grill them for about five minutes a side, until the sauce is burnished but not burned; the sugar will make the sauce inclined to burn, so watch them carefully and err on the side of not blackening them too much (you could do this under the broiler in a pinch -- they would still be good).
Use a sharp, heavy knife to cut the racks into individual ribs, and serve with the rest of the barbeque sauce and lots of napkins.