In a small bowl, mix the chili powder, smoked paprika, brown sugar, black pepper, kosher salt, dry mustard, cayenne pepper, garlic powder and onion powder.: The spice mingle will smell aromatic and slightly sweet, with the smoked paprika announcing a warm smokiness. As you whisk, you will notice the brown sugar softening the sharp edges of the powdered spices, which helps the rub adhere to the meat. This step is vital because even distribution ensures balanced flavor on every bite. If you skip thorough mixing, some bites might be saltier or spicier than others, so take a moment to blend until uniform.
Remove the membrane from the back of the ribs. Cut the rib rack in half so they can fit in the air fryer.: The membrane is a thin, silvery layer that, when removed, lets seasoning penetrate and yields more tender results. Removing it is tactile work, a slight tug that reveals pink meat beneath, and makes the ribs feel more approachable to eat. Cutting the rack helps the ribs lay flat in the air fryer , promoting even circulation of hot air that crisps edges. A common misstep is leaving the membrane on which causes tougher texture, so use a paper towel to grip and pull it off cleanly.
Sprinkle the seasoning mixture over the ribs. Place the ribs in the air fryer meat side down and cook for 20 minutes on 380 degrees. Once the ribs are done, use tongs or a fork to flip them, and cook for 10 additional minutes on 380 degrees.: As you dust the spice blend, the aroma should lift and suggest the profile you will get after cooking. Pat the rub into the surface so it forms an even coat, which encourages a flavorful crust rather than a loose dusting. This contact also helps the kosher salt start drawing flavors into the meat, beginning a subtle brining effect. Avoid piling too much in one area, which can create pockets of intense flavor.
Spread the barbecue sauce over the ribs and cook for 5 more minutes on 380 degrees.: The first cook will set the crust and begin breaking down connective tissues. You should hear a gentle sizzle and see the edges darken as sugars start to caramelize. This stage is about building structure and rendering fat without overcooking. If the ribs are crowded, air cannot circulate properly and results will be uneven, so arrange them so hot air can flow freely.
Once the ribs are done, use tongs or a fork to flip them, and cook for 10 additional minutes on 380 degrees: Flipping helps brown the other side and ensure an even texture. At this point the meat will be pulling back slightly from the bones and the surface will smell sweet and toasted. The additional time finishes the internal breakdown of connective tissues so the ribs are tender when bitten. Be careful when flipping, as the ribs will be hot and juices may splatter, which can cause burns or extra cleanup if you rush the maneuver.
Spread the barbecue sauce over the ribs and cook for 5 more minutes on 380 degrees: The final saucing step creates a glossy, sticky exterior as the sugars in the barbecue sauce caramelize. You will notice a bright, tangy scent mixing with the smoke and sugar, and the sauce will thicken into a lacquered finish. This short final heat seal keeps the interior moist while giving a restaurant style glaze. Watch closely during this step, because sugars can go from beautifully caramelized to burned quickly if left unattended.