Preheat the air fryer. Set it to 375°F (190°C) for 3–5 minutes to warm up. A hot basket helps the tortillas crisp right away.
Season the chicken. In a bowl, toss the cooked chicken with 1 teaspoon chili powder, 1/2 teaspoon cumin, 1/2 teaspoon garlic powder, 1/2 teaspoon onion powder, 1/2 teaspoon smoked paprika, 1/4 teaspoon salt, and a pinch of black pepper.
Adjust to taste.
Prep the salsa. If making your own, combine diced tomatoes, finely chopped red onion, minced jalapeño, chopped cilantro, a squeeze of lime, and a pinch of salt. Stir and set aside so the flavors meld.
Assemble the quesadilla. Lay a tortilla on a board. Sprinkle a thin layer of shredded cheese over half the tortilla.
Add a layer of seasoned chicken and any add-ins. Top with another thin layer of cheese. Fold the tortilla in half to close.
Lightly oil. Spray or brush the outside of the folded tortilla with a little olive oil or cooking spray.
This helps it turn golden and crisp.
Air fry the first side. Place the quesadilla in the basket, leaving space around it. Air fry for 3–4 minutes, until lightly golden.
Flip and finish. Carefully flip with tongs. Cook another 3–4 minutes, until the tortilla is crisp and the cheese is melted.
Thicker quesadillas may need 1–2 more minutes.
Repeat for more. If your air fryer is small, cook in batches. Keep finished quesadillas on a wire rack in a low oven (200°F/95°C) so they stay crisp.
Slice and serve. Let the quesadilla rest for 1 minute. Slice into wedges.
Serve with salsa, lime wedges, and your favorite toppings.