Slice each chicken breast in half lengthwise. Place between plastic wrap and pound evenly to 1/2 inch thickness.
Set up three shallow bowls: one with flour, one with beaten eggs, and one with breadcrumbs mixed with grated Parmesan.
Season chicken with salt and pepper. Dredge each piece in flour, dip in egg, then press into breadcrumb-Parmesan mix.
Heat olive oil in a skillet over medium-high heat. Fry chicken 3–4 minutes per side until golden and crispy. Place on a wire rack to rest.
Preheat oven to 400°F (200°C). Spoon marinara sauce into a baking dish and lay chicken on top.
Add more sauce over chicken and sprinkle mozzarella cheese on each piece.
Bake uncovered for 15–20 minutes until cheese is bubbly and lightly browned.
Garnish with chopped basil or parsley and sprinkle extra Parmesan before serving.
Notes
Use panko breadcrumbs for extra crispiness. Let fried chicken rest on a wire rack before baking to keep crust crunchy. Don’t overload with sauce to avoid sogginess.