Place a sheet of foil or a silicone baking mat on a large baking sheet. (You can also bake the ribs directly on the baking sheet but it’s more difficult to clean later.) Place the oven rack in the middle of the oven.
Place 1 rack St. Louis style ribs meaty side down on the baking sheet. There should be a thin white membrane running along part of the ribs that is face up. Use a paring knife to pry a corner of the membrane up, then grab the membrane with a paper towel (it’s slippery!) and pull it across the length of the ribs to remove it. Sometimes it comes off in pieces and it doesn’t have to be perfect—just get as much as you can.
In a small bowl, whisk together ⅓ cup light brown sugar, 2½ teaspoons salt, 2 teaspoons paprika, and 1 teaspoon garlic powder.
Spread half of the brown sugar mixture over the ribs, then flip and spread the remaining brown sugar mixture on the other side. Try to get any extra brown sugar mixture off the pan and onto the ribs (this makes it easier to clean later).
Bake for 3 hours. You should be able to easily insert a paring knife into the meat of the ribs, and the meat will start to pull away from the bone. If not, cook for an additional 15–30 minutes. Remove from the oven.
Preheat the broiler, positioning a rack about 6 inches away from the broiler.
Drain any grease from the pan. If you used a silicone mat, remove that now, as it can’t go under a broiler.
Slather ⅓ cup bbq sauce over the ribs on both sides.
Broil the ribs, watching them CLOSELY, for 2–3 minutes. You can broil just one side or do both sides. The bbq sauce will be bubbly and then start to get brown in spots. Take them out when they’re done to your liking. Let rest for 10 minutes before slicing.
Serve the ribs with extra bbq sauce if you like.
Notes
My local grocery store sells "pork back ribs" which are actually spare ribs. Those can be substituted here. St. Louis ribs are cut from spare ribs, so they are similar, but spare ribs may need more cooking time because they are larger. This video is really helpful in explaining the difference if you're curious. You can also substitute baby back ribs for this recipe. Want a slightly smoky flavor? Substitute smoked paprika for the regular paprika and/or use a smoky bbq sauce.If you don't have a broiler, bake the ribs another 15 minutes with the bbq sauce on top. Finishing the ribs on the grill (I do this often in the summertime): bake the ribs as directed until tender, slather with bbq sauce, and grill over medium heat until grill marks appear and the bbq sauce is lightly caramelized.Freezing instructions: bake ribs as instructed but do not add bbq sauce or broil. Instead, cut in half for easier storage and wrap each section in foil. Place in a resealable freezer bag for up to 3 months. Defrost and then slather with bbq sauce and broil when you're ready to serve them.