Pound and Season the Chicken: Place each chicken breast between two sheets of plastic wrap and pound with a meat mallet or rolling pin to an even 1.25cm / 0.5-inch thickness throughout. Uneven thickness is the most common reason some parts dry out before the crust finishes browning, so take a full minute per breast here. Season both sides with kosher salt, black pepper, and garlic powder, pressing the seasoning lightly into the surface.
Set Up the Dredging Station: Arrange three shallow bowls in a line: flour in the first, beaten eggs in the second, and a mixture of Italian-seasoned breadcrumbs and 20g / 0.25 cup of the grated Parmesan in the third. The Parmesan in the breadcrumbs adds a faint nuttiness and helps the crust brown more deeply. Work with one cutlet at a time, pressing firmly into each bowl so the coating adheres without bare patches.
Rest the Breaded Cutlets: Transfer the coated cutlets to a wire rack set over a baking sheet and let them rest at room temperature for 10 minutes. This short rest allows the breadcrumb coating to hydrate slightly and bond to the egg, which dramatically reduces the chance of the crust sliding off in the pan. Do not skip this step.
Preheat Oven and Skillet: Position an oven rack in the upper-middle position and preheat the oven to 200°C / 390°F. Set a large oven-safe skillet over medium-high heat and add the neutral oil. The oil is ready when a pinch of breadcrumbs dropped in sizzles immediately and floats to the surface.
Pan-Fry the Cutlets: Working in two batches, lower the breaded cutlets into the hot oil and fry for 3 minutes per side at medium-high heat. The crust should be a deep amber-gold and release cleanly from the pan when it is ready to flip - if it sticks, give it another 30 seconds. Avoid crowding the pan, which drops the oil temperature and produces a greasy, steamed crust rather than a seared one. Transfer the first batch to the wire rack while the second batch fries.
Add Sauce and Cheese: Transfer all four seared cutlets into the skillet (or arrange on a foil-lined baking sheet if your skillet is too small). Spoon 3 tablespoons of warm marinara onto the center of each cutlet, keeping the edges of the crust exposed so they stay crisp in the oven. Lay two to three slices of mozzarella over the sauce, then scatter the remaining 20g / 0.25 cup of Parmesan across all four.
Finish in the Oven: Slide the skillet into the preheated 200°C / 390°F oven and bake for 12 minutes, until the mozzarella is fully melted and bubbling at the edges. For light browning on the cheese, switch to the broiler on high for the final 2 minutes and watch closely - the difference between golden and scorched is about 60 seconds. Use an instant-read thermometer to confirm the thickest part of each cutlet reads 74°C / 165°F before pulling them from the oven. Rest for 3 minutes before plating.
Plate and Finish: Transfer each cutlet to a warm plate and scatter fresh flat-leaf parsley over the top. Serve immediately while the crust retains its texture.
