Preheat your oven to 375°F (190°C).
Prepare the chicken: If necessary, use a meat mallet or rolling pin to pound the chicken breasts to an even thickness of about ½ inch.
Set up your breading station: Place the flour in one shallow bowl, beat the eggs in another bowl, and place the breadcrumbs in a third bowl. Season the flour and breadcrumbs with garlic powder, oregano, salt, and pepper.
Bread the chicken: Dredge each chicken breast in the flour, shaking off any excess. Then dip it into the beaten eggs, ensuring it's fully coated. Finally, coat the chicken in breadcrumbs, pressing gently to adhere.
Heat ¼ inch of olive oil in a large skillet over medium heat. Once hot, carefully add the breaded chicken pieces. Fry for about 4-5 minutes on each side until golden brown and cooked through.
In a baking dish, spread about half of the marinara sauce on the bottom. Place the fried chicken breasts in the dish and top each piece with the remaining marinara sauce. Sprinkle mozzarella and Parmesan cheese evenly over the top.
Bake in the preheated oven for 15-20 minutes, or until the cheese is melted and bubbly.
Remove from the oven and let it cool for a few minutes. Garnish with fresh basil if desired before serving.