Heat oven to 350ºF. Cook and drain noodles as directed on package.
Cook beef and onion in 10-inch skillet over medium-high heat about 6 minutes, stirring occasionally, until beef is brown; drain. Stir in pasta sauce and mushrooms. Heat to boiling, stirring constantly. Pour into ungreased rectangular baking dish, 11x7x1 1/2 inches.
Mix ricotta cheese, spinach, mozzarella cheese, 1/4 cup Parmesan cheese, the salt, pepper and garlic. Spread 3 tablespoons of the cheese mixture over each noodle. Roll up each noodle; cut roll crosswise in half. Place cut sides down in beef mixture.
Cover and bake about 30 minutes or until hot. Serve with additional Parmesan cheese.