Preheat oven to 375°F (190°C). Grease a 9x13-inch casserole dish.
Cook pasta according to package directions until al dente. Drain well.
In the prepared casserole dish, combine pasta, cooked chicken, and marinara sauce. Mix well.
Sprinkle mozzarella and Parmesan cheese over the top.
In a small bowl, combine breadcrumbs, olive oil, and Italian seasoning. Sprinkle evenly over the casserole.
Bake for 25–30 minutes, or until cheese is melted and topping is golden brown.
Remove from oven, garnish with fresh basil or parsley, and serve warm.