Once the sauce is done, spread a thin layer of sauce on the bottom of a lasagna tray. Lay down 3 noodles. Add 1/3 of the sauce, 1/3 of the cottage cheese, 1/3 of the spinach, and 1/4 cup mozzarella cheese. Continue two more times, then top with the remaining lasagna noodles and 1/4 cup of mozzarella. Bake for 30 minutes.