01 - Preheat oven to 400°F. Line a baking sheet with parchment paper or lightly grease it.
02 - Place chicken breasts between two sheets of plastic wrap and pound to about 1/2-inch thickness using a meat mallet.
03 - Season both sides of chicken breasts with salt and freshly ground black pepper.
04 - Set up three shallow bowls: one with flour; one with beaten eggs and milk; one with a mixture of Italian-style breadcrumbs and 1/2 cup grated Parmesan cheese.
05 - Dredge each chicken breast in flour, shaking off excess, then dip into egg mixture, and coat thoroughly with breadcrumb and Parmesan mixture.
06 - Heat olive oil in a large skillet over medium-high heat. Fry chicken breasts in batches for 3 to 4 minutes per side until golden and crisp. Transfer to a paper towel-lined plate.
07 - Prepare spaghetti according to package instructions. Drain and set aside.
08 - Arrange fried chicken breasts on the prepared baking sheet. Spoon marinara sauce over each piece, then top with shredded mozzarella and additional Parmesan cheese.
09 - Bake for 15 minutes until cheese is melted and bubbly and chicken reaches an internal temperature of 165°F.
10 - Serve the chicken breasts over a bed of spaghetti. Garnish with chopped fresh basil if desired.