Line a baking sheet with foil, brush foil with olive oil. Adjust oven rack so that is in the second from the top space. Preheat the oven to 400°F.
Cut the chicken breasts in half and pound to even thickness: Cut through the middle of the chicken breast as if you are going to butterfly it (cutting it open like a book), but cut all the way through to make two equal sized pieces.
After cutting the chicken breasts in half, place them in a gallon sized zip top bag in an even layer, seal it, then pound them to an even thickness using a meat pounder or a rolling pin. You can also place the chicken breasts between two layers of cling wrap instead of a zip top bag if you prefer.
Pat the chicken breasts dry with a paper towel, then season with salt and pepper.
In one shallow dish, mix together panko bread crumbs, grated parmesan cheese, salt, pepper, garlic powder, oregano, and black pepper.
In another shallow dish, whisk one egg.
Dip one chicken breast into the egg, then into the bread crumb mixture. Ensure chicken breast is fully coated in the crumb mixture, and gently press with your hand do help the crumbs stick to the chicken. Place chicken breast on prepared baking sheet, repeat with remaining pieces of chicken.
Place baking sheet in oven on the second from the top rack. Bake for 15 minutes, or until cooked through.
Flip chicken, pour 1/4 cup of marinara sauce over each piece of chicken, then top with cheese. Place back in the oven. Turn on the broiler. Broil for 2-4 minutes, until cheese is melted and bubbly and edges of chicken are browning.