In a large skillet, cook and stir Italian sausage until brown.
Add onions and mushrooms; saute until onions are clear.
Stir in spaghetti sauce, and heat through.
In a medium size bowl, combine cottage cheese, ricotta cheese, grated Parmesan cheese, and eggs.
Spread a thin layer of the meat sauce in the bottom of a 9x13-inch pan.
Layer with ½ of the uncooked lasagna noodles, ½ of cheese mixture, ¾ cup mozzarella cheese, and ½ of meat sauce. Continue layering until all ingredients are used, reserving ½ cup mozzarella.
Cover pan with aluminum foil.
Bake in preheated oven for 45 minutes. Uncover, and top with remaining half cup of mozzarella cheese.
Bake for an additional 15 minutes.
Remove from oven, and let stand 10 to 15 minutes before serving.
Notes
Feel free to substitute Ricotta and Cottage Cheese with the other. In lasagna, ricotta cheese and cottage cheese are perfectly interchangeable.