Prep the chicken. Pat the chicken dry with paper towels. Cut into even, bite-size nuggets so they cook at the same rate.
Preheat. Oven: 425°F (220°C). Air fryer: 400°F (205°C).
Line a baking sheet with parchment and lightly oil it, or spray the air fryer basket.
Make the coating. In a shallow bowl, whisk together Parmesan, almond flour, garlic powder, onion powder, smoked paprika, salt, and pepper. Add Italian seasoning or cayenne if using.
Beat the eggs. In another bowl, beat the eggs until smooth.
Coat the nuggets. Dip chicken pieces in egg, let excess drip, then press into the Parmesan mixture. Turn to coat well, pressing lightly so it adheres.
Arrange. Place coated nuggets on the prepared baking sheet or in the air fryer basket, leaving a little space between pieces for airflow.
Cook. Oven: Bake 15–18 minutes, flipping halfway.
For extra color, broil 1–2 minutes at the end if needed.
Air fryer: Cook 10–12 minutes, shaking or flipping at the halfway point. Work in batches to avoid crowding.
Check doneness. Internal temperature should reach 165°F (74°C). The coating should be golden and crisp.
Rest and serve. Let sit 2 minutes to set the crust.
Squeeze lemon over the top if you like and serve with your favorite keto-friendly dip.