Preheat oven to 400°F. Have a 2- to 3-quart baking dish ready.
In a large mixing bowl, stir together uncooked pasta, marinara sauce, chicken broth, chicken, and 1 cup of the mozzarella. Transfer to the baking dish. Top with the remaining 1 cup of mozzarella cheese. Cover with foil and bake for 30 minutes.
Meanwhile, in a small bowl, combine the bread crumbs, parmesan cheese, dried Italian herbs, and 1 tablespoon melted butter.
Remove the foil and sprinkle the top of the casserole evenly with the breadcrumbs. Bake for another 10 minutes, uncovered, or until golden brown and casserole is bubbly all over.
Let stand for 5-10 minutes before serving.