Preheat the oven to 375°F (190°C).

Prepare the chicken breasts by placing them between two sheets of plastic wrap. Use a meat mallet or rolling pin to pound them to an even thickness, about 1 inch thick. Season both sides with salt, pepper, garlic powder, and oregano.

Set up a breading station: Place the flour in one shallow dish, beat the eggs in a second shallow dish, and mix the breadcrumbs with half of the grated Parmesan cheese in a third shallow dish.

Dredge each chicken breast in flour, shaking off the excess. Dip it into the beaten eggs, allowing the excess to drip off, then coat it in the breadcrumb mixture, pressing gently to adhere.

In a large skillet, heat olive oil over medium-high heat. Once hot, add the breaded chicken breasts, cooking for 3-4 minutes on each side until golden brown. You may need to do this in batches to avoid overcrowding the pan.

Once all the chicken is cooked, spread 1 cup of marinara sauce in the bottom of a baking dish. Place the chicken breasts on top of the sauce.

Spoon the remaining marinara sauce over the chicken breasts, and sprinkle with the remaining mozzarella cheese and Parmesan cheese.

Bake in the preheated oven for 20-25 minutes, or until the cheese is melted and bubbly, and the chicken is cooked through (internal temperature should reach 165°F or 75°C).

Remove from the oven, let it cool for a few minutes, and garnish with fresh basil leaves before serving.