In the same way you can make lasagna with raw noodles, you can make manicotti with raw pasta (tubes; or use large shell pastas).
box of manicotti (usually 12-16 per box); substitute large shells, if you prefer
spaghetti sauce, about 8 cups (home-made or from a jar; with or without onion, mushrooms, meat, etc.)
1 1/2 - 2 c mozzarella cheese, or to taste
1 pint (1 pound) ricotta (or cottage cheese - small curd is best)
1 c parmesan cheese, grated
1 T chives
1 T basil or oregano or marjoram or tarragon 1/2 c bread crumbs or panko for thickening, if needed
A 13" x 9" casserole dish Drain the ricotta cheese, although it's usually not runny. Ricotta used to come in 16-oz. containers. The last one I had was 15 oz. It made no difference. If you can find only 10-oz. containers, make up the rest with cream cheese or cottage cheese.
If using cottage cheese, drain it, as it always has too much liquid. Put it in a strainer and let it sit for 15-30 minutes. This step is so the dish isn't "watery." (Ask how I know this!)
Beat 3 or 4 eggs well. Mix in the drained cottage cheese. I add about 1 c grated parmesan cheese (the Kraft kind in the green container, but you can use the real stuff if you're feeling rich). I also put some herbs in. Not a lot and not many kinds. Usually some chives and one other herb (basil or oregano). (If onions are in the sauce, I add a second herb.)
The consistency of the filling should be soft and moist but not runny, or you won't be able to work with it. The filling should "hold its shape" in a spoon, rather like a thick cake batter. When cooked, the eggs will firm up the filling, but if it looks a bit to runny, put in some parmesan cheese, bread crumbs (not croutons, though you could crush them), or Japanese bread crumbs, which are called panko (good to have on hand, so don't be aghast at the size of the box; tightly roll down inner wrapper and secure with a clothespin).
If you prefer, make a filling from cooked and drained ground meat; or chicken breasts. Another option is to wilt spinach and squeeze out as much water as possible; chop finely. If the filling seems "loose" thicken it, as described above.
Stuff the manicotti, using a teaspoon. Or, substitute large shells.
Place 3/4 - 1 cup sauce in the bottom of the dish. I add 2-3 T water to give a good "steamy" start to the noodles, but this is optional.
Place stuffed manicotti on the sauce and pour on more to just cover. (If you put in too much, it will boil over during baking.)
Cover with tin foil and bake at 375 until bubbly, about 1 hour. At about 45 minutes, insert a paring knife into the pasta to check on doneness. The pasta should offer the barest resistance, like putting the knife tip into the flesh of a peeled apple.
If the sauce is looking thick and "chunky", dribble a little water on top of the manicotti. The sauce will not cook down, at this point, so don't flood the casserole. This water is just a tad to keep the sauce from drying out.
Put some mozzarella on top and return to the oven to melt, uncovered, about 5 minutes. Watch. You don't want the cheese to burn.
Stick a paring knife down into the dish again. The pasta should offer no resistance. By the time the cheese is melted, if the pasta still shows some resistance, cover with waxed paper and give the dish a zap in the microwave. Start with 1 minute, then check.