1Heat oven to 400º F. Grease rectangular baking dish, 13x9x2 inches. Cook sausage and onion in 10-inch skillet over medium-high heat, stirring occasionally, until sausage is no longer pink; drain. Stir in spaghetti sauce; cook until hot.
2Spoon sausage mixture on half of each egg roll wrapper to within 1/2 inch of edge. Top with mushrooms, 1/2 cup of the mozzarella cheese and the Gorgonzola cheese. Moisten edges of wrappers lightly with water. Fold over filling; press edges to seal. Place in baking dish.
3Sprinkle with remaining mozzarella cheese. Bake uncovered 15 to 20 minutes or until calzones are hot and cheese begins to brown. Serve with additional spaghetti sauce in desired.