Prep the chicken. Pound each breast between plastic wrap to an even ½-inch thickness so they cook uniformly. Pat them completely dry with paper towels — this is the step that matters most for getting a good crust. Season both sides generously with salt and pepper.
Set up your breading station. Place flour in one shallow dish, beaten eggs in a second, and breadcrumbs mixed with ¼ tsp of salt in a third. Dredge each chicken breast in flour, shaking off excess, then dip into the egg mixture, letting any drip fall away before pressing it firmly into the breadcrumbs until fully coated.
Cook the chicken. Heat 2 tablespoons of olive oil in a large skillet over medium-high heat (the oil should shimmer when ready). Add the breaded cutlets in batches — don't overcrowd the pan or they'll steam instead of brown. Cook for 4-5 minutes per side until golden and crispy, then transfer to a paper towel-lined plate. The internal temperature should reach 165°F.
Assemble. Preheat your broiler. Spread about ½ cup of marinara in the bottom of a baking dish or along each individual serving plate. Place cooked chicken on top, spoon another generous tablespoon of sauce over each piece, and layer with mozzarella slices. Sprinkle Parmesan cheese across everything.
Melt under the broiler. Broil for 2-3 minutes until the cheese is bubbly and starting to brown in spots — watch it closely because broilers vary wildly. Serve immediately while hot.
