Cook noodles according to package directions, until just al dente.
In a large pot, saute beef, sausage and chopped onion until beef is cooked through.
Drain grease from the meat mixture.
To the beef mixture, add tomato sauce, crushed tomatoes, and diced tomatoes. If sauce appears to be too thick, add in the cup of water.
To the sauce, add in the basil, oregano, sugar, salt and pepper.
Let sauce simmer on the stovetop for 30-45 minutes.
To make the cheese mixture, combine cottage cheese, eggs, dried parsley and parmesan cheese in a medium sized bowl.
To assemble the lasagna, start with putting about a cup of sauce on the bottom of your baking dish.
Next, add a layer of noodles.
Put 1/3 of the cottage cheese mixture on top of the noodles and spread evenly over the layer of noodles.
Pour on 1/3 of the meat sauce and spread evenly.
Cover with a layer of sliced mozzarella.
Repeat this process 2 more times, leaving the top layer of mozzarella cheese off the top of the lasagna for now.
Place lasagna in oven and bake for 30 minutes.
Take the lasagna out of the oven, place the top layer of mozzarella cheese on top and return to oven for an additional 15 minutes.
Let the lasagna rest out of the oven 15 minutes before you cut it. It will cool slightly and set up for you.