I was craving mac and cheese, but w/ a grown-up feeling to it. I noticed I had a left over can of pureed pumpkin from the holiday's, so this is what I came up with. Make sure to use the best of every ingredient, ie: best cheese, best oil, etc., because it really does make a difference in taste!
Heat oven to 350. Lightly spray a 2-quart casserole pan w/ cooking spray. Cook pasta as directed, drain, set aside. In lg saucepan, over medium heat, Melt butter. Stir in flour, salt and white pepper.
Whisk in light cream and milk. Cook, stirring, until bubbly and thick. Stir in fontina and 1/4 cup parmesan cheese,pumpkin and 1 tbsp sage. Keep stirring until cheeses are melted. Spoon pasta into casserole pan. Stir cheese sauce into pasta. Mix until well incorporated.
In medium bowl, combine bread crumbs, remaining parmesan cheese, walnuts and oil. Mix well. Sprinkle over pasta and sauce. Bake, uncovered for 30 mins. Sprinkle w/ remaining sage and serve.