Preheat the oven to 375 Degrees F and grease a 7x11 or 9x13 inch baking dish with nonstick spray.
Add the zoodles to the bottom of the casserole dish in an even layer, then top with marinara.
Next, add the diced chicken, topped with the mozzarella cheese.
Break the parmesan crisps into small pieces. You can do this by hand, or by placing them in a zip top bag and hitting them with a rolling pin or heavy pan. Don't make them too small or you will lose some of the crispiness!
Add the crushed parmesan crisps to the top of the casserole and bake it in the preheated oven for 20 minutes or until the mozzarella cheese is completely melted and the sauce and chicken are hot. If desired, you can also place it under the broiler for a few minutes to further brown the cheese.