Boil manicotti noodles 8 minutes and drain; set aside.
Meanwhile make the filling by combining sausage, 1 cup mozzarella, 1 cup provolone, breadcrumbs and eggs.
Pour 3/4 cup sauce into a greased 9x13 baking dish and spread so it covers the whole bottom of the dish.
Stuff manicotti with the filling.
Arrange the filled manicotti in the baking dish in a single layer (you may need an additional 8 inch square baking dish for all of the manicotti or use a large lasagna baking dish, if you prefer. Sometimes I freeze the remaining stuffed manicotti shells to use for another meal or snack).
Top the manicotti with the remaining spaghetti sauce.
Cover with foil and bake at 375 degrees for about 25 minutes.
Uncover and sprinkle with remaining mozzarella, provolone and parmesan cheese.
Bake for another 5-10 minutes until cheese is melted and bubbly.