Cook shells according to package directions. Drain and set aside.

Preheat oven to 350°F.

Spoon ½ cup of Classico® Creamy Alfredo Sauce evenly into bottom of 13x9 baking dish.

In medium bowl, mix ricotta cheese, pumpkin, parmesan cheese, egg, walnuts, black pepper, sage, and 1 cup of the mozzarella cheese.

Stuff each shell with cheese mixture and arrange in baking dish seam side down. Spoon remaining sauce evenly over shells.

Cover tightly with foil and bake for 30 minutes.

Remove foil and sprinkle remaining 1 cup of mozzarella cheese on top. Bake for additional 5 minutes or until cheese is melted and bubbling.

Allow to rest for 5 to 10 minutes before serving.