Preheat the oven to 200°C (400°F).
Place the chicken breasts between two sheets of parchment paper and gently pound them to an even thickness.
Season both sides of the chicken with salt, black pepper, and Italian seasoning.
Prepare three shallow bowls: one with flour, one with beaten eggs, and one with breadcrumbs mixed with ½ cup Parmesan cheese and garlic powder.
Dip each chicken breast into the flour, shaking off any excess.
Dip the floured chicken into the beaten eggs.
Press the chicken into the breadcrumb and Parmesan mixture, coating both sides evenly.
Heat the olive oil in a large skillet over medium heat.
Cook the breaded chicken for about 3–4 minutes per side, until golden brown. Work in batches if necessary.
Transfer the chicken to a lightly greased baking dish.
Spoon marinara sauce over each chicken breast.
Sprinkle the mozzarella and remaining Parmesan cheese evenly over the top.
Bake for 15–20 minutes, or until the chicken is fully cooked and the cheese is melted and lightly golden.
Remove from the oven and let the chicken rest for about 5 minutes.
Garnish with fresh parsley or basil and serve hot with pasta, roasted vegetables, salad, or crusty bread.