Preheat oven to 375°F Cook noodles according to package directions. Drain noodles and rinse with cold water.
Mix ricotta, egg and 1 cup mozzarella in bowl, set aside.
If you decided to use the fresh mushrooms chop and sautee, set aside.
If you decided to use frozen spinach drain out excess water.
Cook sausage (beef) in skillet over medium heat until browned and crumbly; drain fat.
Spread 1/2 cup sauce in a 9 x 13 inch baking dish. Spread 3 tablespoons ricotta mixture on each noodle; top with some sausage (mushrooms & spinach). Roll up each noodle. Arrange seam sides down in baking dish.
Top roll-ups with remaining sauce and mozzarella. Bake, loosely covered, for 15 minutes. Remove cover, bake for 10 more minutes or until brown and bubbly.
*You may prepare this dish up to 2 days before baking. Wrap them seperately in foil and put in freezer bag. Let thaw at room temperature before baking or microwaving.