Preheat the air fryer. Set it to 375°F (190°C) for 3–5 minutes.
A preheated basket helps the tortilla crisp quickly.
Scramble the eggs. In a small skillet over medium heat, melt 1 teaspoon butter or warm 1 teaspoon oil. Beat 2 eggs with a pinch of salt and pepper. Cook, stirring gently, until just set and still soft.
Remove from heat.
Prep the fillings. If using veggies like mushrooms or peppers, sauté them briefly to soften and remove moisture. Chop cooked bacon or sausage into small pieces. Pat any juicy ingredients dry.
Assemble the quesadilla. Lay a tortilla on a cutting board.
Sprinkle half the cheese on one half of the tortilla. Top with scrambled eggs, meats, and veggies, then add the remaining cheese. Fold the tortilla in half to make a semicircle.
Press lightly to seal.
Brush for extra crisp. Lightly brush the outside of the folded tortilla with oil or melted butter. This boosts browning and crunch.
Air fry. Place the quesadilla in the air fryer basket. If it tries to lift, press it down or use a small rack or toothpicks to secure.
Cook at 375°F (190°C) for 5–7 minutes, flipping once halfway through. It’s done when the tortilla is golden and the cheese is melted.
Rest and slice. Let it sit for 1 minute to set the cheese. Slice into wedges and serve with salsa, hot sauce, or a dollop of Greek yogurt.