Preheat your oven to 350°F and prepare a 9×9-inch baking dish or a 2 to 2.5-quart casserole dish by spraying it with cooking spray to prevent sticking.
Cook the ziti pasta according to the package directions until al dente. This is crucial as it will continue to cook in the oven. As the pasta cooks, take the opportunity to shred the chicken to save time. You want it ready to mix in.
Once the pasta is cooked, drain it well. Do not rinse it, as the starch helps the marinara sauce cling to it. Return the pasta to the pot.
To the pot, add the shredded chicken, marinara sauce, oregano, and if you like a little kick, sprinkle in some red pepper flakes. Stir everything together until it’s well combined and coated in the sauce.
Transfer half of this delicious mixture into the prepared baking dish, spreading it evenly on the bottom.
Sprinkle 1 cup of mozzarella cheese and ½ cup of Parmesan cheese over the top of this mixture. This layer creates a delightful cheesy goodness.
Now, pour the remaining half of the saucy pasta mixture over the cheese. This ensures that each bite is as flavorful as the last.
Add the remaining 1 cup of mozzarella cheese and ¼ cup of Parmesan cheese to the top.
If you want to prepare this in advance, cover the dish tightly with foil or plastic wrap and refrigerate for up to 2 to 3 days. When you're ready to bake, allow the casserole to sit at room temperature for about 45 minutes before baking. If frozen, remember to thaw it before cooking.
Bake uncovered for about 20 to 25 minutes or until the cheese is golden brown and bubbly on top. I recommend placing the baking dish on the middle oven rack and rotating it halfway through for even browning.
Storage Tip: Leftovers can be stored in an airtight container in the fridge for up to 5 days or in the freezer for up to 3 months. When reheating leftovers, a quick 30-second zap in the microwave works wonders.
