Prep the chicken: Halve the chicken breasts horizontally to make 4 thin cutlets. If needed, gently pound between sheets of baking paper until even thickness (about 1/2 inch).

Make the marinade: In a bowl, mix yoghurt, 1/2 tsp salt, 1/4 tsp pepper, 1/2 tsp garlic powder, and 1/2 tsp paprika. Add the egg if using for extra binding.

Marinate: Add chicken to the yoghurt mixture and coat well. Cover and chill for at least 30 minutes, up to 12 hours. Longer = more tender and flavorful.

Set up the coating: In one shallow dish, add flour plus 1/2 tsp salt and 1/4 tsp pepper. In a second dish, combine breadcrumbs, Parmesan (if using), remaining garlic powder, paprika, onion powder, and oregano.

Coat the chicken: Shake excess marinade off each piece. Dredge in flour, then press into the breadcrumb mixture so it adheres all over. Let coated pieces rest 5 minutes so the crust sets.

Preheat the air fryer: 400°F (200°C) for 3–5 minutes. Lightly spray the basket with oil.

Air fry in batches: Place schnitzels in a single layer. Lightly spray tops with oil for even browning. Cook at 400°F (200°C) for 6–8 minutes per side, flipping once, until golden and an internal temperature of 165°F (74°C). Time varies by thickness and air fryer model.

Rest and serve: Let schnitzels sit 2–3 minutes. Finish with a squeeze of lemon and chopped herbs. Serve with a simple salad, slaw, or potatoes.