Preheat your oven to 375°F and grease a 9x13-inch baking dish with olive oil. Cook the ziti according to package directions until just shy of al dente since it'll finish cooking in the oven.

While the pasta cooks, heat olive oil in a large skillet over medium heat. Brown the meatballs on all sides, about 8-10 minutes total. They don't need to cook through completely since they'll finish in the oven.

In a large bowl, combine ricotta, egg, Italian seasoning, garlic powder, half the mozzarella, and half the Parmesan. Mix until smooth and creamy.

In your prepared baking dish, layer half the cooked ziti, then dot with half the ricotta mixture. Add all the browned meatballs, pour marinara sauce over everything, then layer the remaining pasta and ricotta mixture. Top with remaining mozzarella and Parmesan.

Cover tightly with foil and bake for 30 minutes. Remove foil and bake another 15 minutes until the cheese is golden and bubbling around the edges. Let it rest 5-10 minutes before serving.