Pound the chicken breasts to an even thickness of about 1/2 inch. This helps them cook through evenly and keeps the texture tender rather than dry.
Set up a breading station: place flour in one shallow dish, beaten eggs in a second, and a mixture of breadcrumbs, Parmesan, Italian seasoning, garlic powder, salt, and pepper in a third. Stir to combine.
Dredge each chicken cutlet in flour, tapping off any excess. Dip into the eggs, letting the excess drip off, then coat thoroughly with the breadcrumb mixture. Lightly press to ensure the crust adheres well.
Heat olive oil in a large skillet over medium heat. When shimmering, add the breaded chicken in a single layer. Cook 3–4 minutes per side until the crust is deeply golden and the chicken is nearly cooked through. Move to a parchment-lined sheet tray.
Top each browned cutlet with 1–2 tablespoons of marinara sauce, then lay slices or a handful of mozzarella on top.
Bake in a preheated 425°F (220°C) oven for 12–15 minutes, or until the cheese is melted and bubbling and the chicken reads 165°F (74°C) on an instant-read thermometer. If you like, switch to the broiler for 1–2 minutes to deepen the golden color, watching closely so the cheese doesn't burn.
Rest briefly for 5 minutes, then garnish with fresh basil and optional grated Parmesan. Serve with pasta, a green salad, or crusty bread to soak up extra sauce.