Preheat your oven to 400°F.
In a 9x13-inch baking dish, add the uncooked pasta, marinara sauce, chicken broth, Italian seasoning, and garlic powder. Stir to combine.
Add the frozen meatballs, spreading them evenly over the pasta mixture.
Cover the baking dish tightly with aluminum foil and bake for 35 minutes.
Remove the foil, sprinkle the mozzarella cheese evenly over the top, and return to the oven. Bake uncovered for an additional 10-15 minutes, or until the cheese is melted and bubbly.
Let the casserole rest for 5 minutes before serving.