Set the oven's temperature to 400°F and use parchment paper to line a baking dish or sheet pan.

Combine the garlic powder, onion powder, salt, and black pepper in a small bowl and whisk until well blended.

Pat the chicken dry with paper towels so the coating sticks and browns, then apply the seasoning mixture to both sides. Place the seasoned chicken in the prepared baking dish in a single layer.

In a bowl, mix together the mayonnaise, garlic powder, ½ cup Parmesan, salt, and pepper until thoroughly mixed.

Using a sharp knife, slice each chicken breast in half horizontally to make 8 thinner cutlets. Cover each piece with a layer of the mayonnaise mixture.

If desired, sprinkle a little extra Parmesan cheese over the top.

Bake at 400°F for 20 to 25 minutes, until the top is well browned and a meat thermometer reads 165°F.

Let the chicken rest for 5 minutes so the juices settle, then sprinkle with the parsley and serve.