Preheat the oven to 400° and lightly grease a rimmed baking sheet.
If the chicken breasts are large, you can slice them in half, width-wise. For medium chicken breasts, place each one in a zip-lock bag and pound it a little with a meat tenderizer. For small, thin chicken breasts, you don’t need to do anything to it.
Breading the chicken:
Combine flour, salt, pepper, and garlic powder in the first one. Whisk egg with some salt and pepper in the second bowl. Mix Italian bread crumbs, grated Parmesan cheese, garlic powder, onion powder, salt, and pepper in the last bowl.
First – Dip each chicken breast in flour mixture to lightly coat it all over.
Second – Dip flour coated chicken breast in egg mixture on both sides.
Third – Place chicken breast into the bowl with bread crumb mixture and flip it over a few times. Gently pat as you’re flipping the chicken to make sure the bread crumbs get onto the chicken nicely.
Repeat with remaining chicken cutlets.
Place breaded chicken breasts onto the baking sheet, leaving just a little space in between.
Bake chicken for 18-20 minutes, depending on the thickness of chicken breasts.
Warm up marinara sauce if it’s cold.
Take the baking sheet out of the oven (close the oven door to keep the heat in) and spoon marinara sauce over each chicken breast. Use as little or as much as you want, just make sure to cover the whole top evenly.
Spread shredded Mozzarella cheese over the top of each chicken breast and sprinkle some oregano over cheese.
Place the baking sheet back in the oven and cook for about 7 more minutes, until all the cheese is melted.