1. If you have one full rack of un-cut baby back ribs, I would recommend cutting them in half. This makes them easier to manipulate later on rather than trying to move around one large set of ribs.
2. Flip the ribs over and attempt to remove the “silverskin.” The silverskin is a layer of connective tissue usually found on the underside of ribs (but can also be found on tenderloin cuts as well). You do not absolutely have to remove this layer under the ribs because it can be a little difficult, but the ribs do turn out a bit better when you do. The dry rub can also reach the meat on the underside of the ribs better this way. In order to remove the silverskin, you need to use a knife edge to slice a piece of the sliver skin sitting on top of a bone. Don’t do this over the meat area because you could damage the meat. Using dry hands or a paper towel, grab hold of the flap you created and simply pull the silverskin off. Repeat this process until you’ve gotten all or most of it off. Sometimes the silverskin comes off very easily and other times you will have to work for it.
3. Set the ribs aside and get the dry rub ready. In a bowl, add in the onion powder, garlic powder, brown sugar, smoked paprika, cumin, salt, pepper, and chili powder.
4. Next, add in the oil and mix the dry rub very well using a spoon or your hands (this is where latex gloves really pay off).
5. Apply the dry rub evenly over the entire (top and bottom) rack of rib by really rubbing it all over.
6. Place the ribs into a seal-able plastic bag or large air tight container to let them marinate in the rub. Again, cutting the ribs in half makes this much easier to accomplish. Let the ribs sit like this at room temperature for an hour or overnight in the fridge. If you leave them in the fridge over night, then let them sit outside the fridge for 30 min. to an hour before you are ready to cook them so they get to room temperature.
7. After an hour has passed, pre-heat the oven to 250º F.
8. Tear off a long sheet of aluminum foil and lay it over the baking sheet before placing the ribs on top of the foil. Set the baking sheet and ribs so that the longer sides are facing you.
9. Now, you want to fold the foil so that it creates a pouch for the ribs. I usually start by folding half of the right or left side of the foil over the ribs.
10. Then I fold the other half over as well. You may need to tuck some of the foil underneath the ribs if the foil extends beyond the edge of the ribs. The last step is to fold up and roll the open edges at the top and bottom so that they close the pouch.
11. Repeat this process with the other half of ribs, so that you have two pouches.
12. When the oven has reached 250º F, place the baking tray with the pouches of ribs on the middle rack of the oven. Then forget about them for 4 hours. You do not need to open the oven or check on the ribs at all during this time.
13. After four hours, the ribs are done cooking, so remove them from the oven and set the oven to broil on High.
14. The next step is tricky because you want to drain the pouches of ribs, which are now filled with liquid after cooking. Carefully make a small opening in the pouches and drain them into the sink or some other container. You may need to move the ribs from the tray to do this. The idea is to get rid of the liquid without spilling that liquid all over the baking tray.
15. With the liquid gone, open up the pouches and let the ribs breathe! They will look a little strange at first, but that’s ok!
16. Once the pouches are opened, place the ribs under the broiler for 3 – 5 minutes until they take on a little color and look a little crispier. If any grease from the ribs catches fire, simply take them out and remove the greasy area from the pan before returning the ribs to the broiler. You will need to watch the ribs carefully at this point so they don’t burn.