Averie Cooks

0 Preheat oven to 350F and spray a 9x9-inch baking dish or 2 to 2.5-quart casserole dish with cooking spray; set aside.
1 Cook the pasta according to package directions to al dente. Tip - While pasta is cooking, shred the chicken to get ahead.
2 When the pasta is cooked to al dente, drain it, return it to the pot, add the shredded chicken, marinara, oregano, optional but recommended red pepper flakes, and stir to combine. Tip - Do NOT rinse the pasta as the starch helps it blend and bind with the marinara sauce.
3 Turn out HALF this saucy pasta mixture into the prepared baking dish.
4 Evenly sprinkle 1 cup mozzarella cheese and 1/2 cup Parmesan cheese over the top.
5 Turn out the remaining half of the saucy pasta over the top, and then add the remaining 1 cup mozzarella, and 1/2 cup Parmesan. Tip - If you want to make this in advance, stop now, cover the dish tightly with foil or plastic wrap, and refrigerate for up to 2-3 days. When you're ready to bake, set the casserole dish on your countertop for about 45 minutes so it can come up to nearly room temp before baking, and then bake as directed. You can also freeze this for up to 3 months prior to baking, thaw, and bake as directed. However, most people will not have space for a large baking dish in their freezer.
6 Bake uncovered for about 20 to 25 minutes, or until the cheese is as golden browned on top as desired. Tip - I suggest baking on the middle oven rack and rotating the baking dish once midway through baking for even browning. 
7 Storage - Leftovers will keep airtight in the fridge for up to 5 days or in the freezer for up to 3 months. I store all leftovers in individual serving size microwave-safe containers and reheat in the microwave for about 30 seconds.