Cook the chicken nuggets according to the package directions. Or if you're making homemade chicken nuggets, cook through per the recipe.
When the nuggets are done, set them aside. If any nuggets are large, cut them in half or into bite sized pieces.
Bring a large pot of salted water to a boil. Add the rotini and cook 2 minutes less than the box recommends for "al dente".
While the pasta boils, gather the rest of your ingredients and preheat the oven to 375°F.
Once the pasta is cooked, drain it and transfer to a large bowl. Add the marinara sauce and stir until everything is evenly coated.
Spray a 9×13-inch baking dish with cooking spray. Spread half of the pasta mixture in the bottom of the dish. Top with half of the chicken nuggets.
Sprinkle 1 cup mozzarella and ¼ cup parmesan over the nuggets. Add the remaining pasta, then the rest of the nuggets, and finish with the remaining mozzarella and parmesan cheese.
Bake for 25–35 minutes, until the casserole is hot and bubbling around the edges. If the cheese needs more color, broil on high for about 2 minutes until lightly golden.
Let the casserole rest for 5 minutes before serving so it sets up and scoops easily.