Cook manicotti shells according to instructions on the box. When shells are cooked al dente, drain in a colander. Separate the shells so they do not have a chance to stick together. Lay them out on a piece of plastic wrap until ready to use.
Meanwhile, mix the ricotta cheese, basil and eggs. Stir until well combined.
Ladle enough sauce into the bottom of the sprayed baking dish to cover the bottom completely.
Carefully stuff each shell with the prepared mixture using a small spoon. (I have an old silver baby spoon that I use) Place them in the baking dish about a 1/2 inch apart. Spoon the remaining sauce over the top of the manicotti.
Cover with foil and cook for 20 minutes at 350°. After 20 minutes, remove foil and place 2 slices of thinly cut mozzarella cheese over each manicotti. Place back in the oven for 5 or 6 more minutes to melt the cheese. Serve topped with Parmesan cheese.