Preheat the Oven: Preheat your oven to 400°F (200°C). Line a baking sheet with parchment paper or aluminum foil and lightly coat with cooking spray.
Prepare the Chicken: Place the chicken breasts between two pieces of plastic wrap and pound them to an even thickness using a meat tenderizer or rolling pin. This helps ensure they cook evenly.
Set Up the Breading Station: In a shallow dish, place the flour. In another shallow dish, beat the eggs. In a third shallow dish, combine the breadcrumbs, Parmesan cheese, garlic powder, onion powder, oregano, basil, salt, and pepper.
Bread the Chicken: Dredge each chicken breast in the flour, shaking off any excess. Dip it into the beaten eggs, allowing any excess to drip off. Finally, coat the chicken in the breadcrumb mixture, pressing lightly to adhere.
Bake the Chicken: Place the breaded chicken breasts on the prepared baking sheet. Lightly spray the tops with cooking spray. Bake in the preheated oven for 20-25 minutes, or until the chicken is golden brown and cooked through (an internal temperature of 165°F or 74°C).
Add the Sauce and Cheese: Remove the baking sheet from the oven. Spoon marinara sauce over each chicken breast and sprinkle with shredded mozzarella cheese. Return to the oven and bake for an additional 5-7 minutes, or until the cheese is melted and bubbly.
Garnish and Serve: Remove the chicken parmesan from the oven and let it rest for a few minutes. Garnish with fresh basil leaves if desired. Serve hot with your favorite pasta or a side salad.