Preheat oven to 400°F (200°C). Pound chicken breasts to even thickness using a meat mallet.
Set up a breading station: place flour in one shallow dish, beaten eggs in another, and mix breadcrumbs, Parmesan cheese, garlic powder, oregano, salt, and pepper in a third dish.
Dredge each chicken breast in flour, dip in egg, then coat thoroughly with breadcrumb mixture.
Heat olive oil in a large oven-safe skillet over medium-high heat. Cook chicken for 3-4 minutes per side until golden brown.
Transfer skillet to oven and bake for 15 minutes.
Remove from oven, top each chicken breast with marinara sauce, mozzarella cheese, and a sprinkle of Parmesan.
Return to oven and bake for an additional 5-7 minutes, or until cheese is melted and bubbly.
Garnish with fresh basil if desired and serve immediately.
Notes
Serve with a side of pasta or a fresh green salad for a complete meal.