Directions

1. Preheat oven to 375 degrees F. Lightly butter an 11"x13" baking pan or 4 ramekins/oven-proof bowls
2. Cook macaroni in salted boiling water according to package directions.
3. While macaroni cooks, melt the butter in a medium pot over low heat. 
4. Add the onion and cook, stirring occasionally, for about 10 minutes, to allow the onions to caramelize. 
5. Turn heat up to medium and cook, just until butter begins to brown. 
6. Add the flour and whisk until you have a very sticky dough. 
7. Continue whisking the butter-onion-flour mixture for 1 minute.
8. Slowly whisk in the milk or half-and-half a little at a time, to form a thick sauce.
9. Continue whisking as you add the pumpkin and the cup of the white cheddar. You should have a very creamy orange sauce. 
10. Season with nutmeg, salt and pepper.
11. Drain the pasta and return it to its pot. Use a rubber spatula to scrape all of the sauce over the pasta and stir to coat the pasta evenly.
12. Scrape the sauced pasta into the prepared pan(s) and top with the reserved cheddar and the breadcrumbs.
13. Bake for 18-22 minutes or until the cheese is very bubbly and the breadcrumbs are lightly browned. Serve hot.