Cook noodles according to package directions. Drain; set aside. In skillet cook mushrooms and 3/4 teaspoon salt in hot olive oil over medium heat until tender and no liquid remains. Remove; set aside. Add bacon to skillet; cook until crisp. Remove; set aside. Discard all but 1 tablespoon drippings in skillet. Add onion; cook in drippings until tender. Add sage; cook 30 seconds. Add the pumpkin, milk, pepper, vinegar, and 1 teaspoon salt. Heat through.

In a greased 3-quart oval baking dish spread 1/2 cup pumpkin sauce. Cover bottom of dish with 4 noodles, trimming to fit. Spread one-third of sauce over noodles. Layer with one-third each of mushrooms, bacon, ricotta, mozzarella, and Parmigiano-Reggiano. Repeat layers twice. Bake, uncovered, in 400 degree F oven for 40 to 45 minutes. Let stand for 15 minutes. Makes 12 servings.