This is great comfort food and taking advantage of all the wonderful fall squash available.  I used these smaller Honeynut Squash but Butternut works great. I roasted the squash for extra flavor.

Ingredients

1 lb pasta (I use trottole or ribbed elbow)
6 tbsp unsalted butter, divided
1/4 cup all purpose flour
3 1/2 cups whole milk (I used skim)
pinch of nutmeg
pinch of cayenne
dash of smoked paprika
Salt, to taste
4-6 cups grated cheese
(I use sharp white and gruyere, how much you use is up to how cheesy you like it)
1/4 cup grated parmesan cheese
1/2 cup plain breadcrumbs
3 cups roasted butternut squash (recipe below)

Directions

Preheat oven to 350˚F and butter a 2 quart baking dish.

Bring a large pot of salted water to a boil, and cook the pasta to a al dente.

Meanwhile make roux by melting 4 tbsp of the butter in a dutch oven or heavy bottomed pan over medium low heat. When butter is melted, add flour and cook, whisking for about 2 minutes or until golden brown.

Slowly whisk in milk and mix until it is all incorporated. Switch to a wooden spoon and cook over medium heat, stirring constantly,until it thickens and coats the back of a spoon. Season with salt, pepper, cayenne and nutmeg. Remove from heat and add cheese. Stir until melted. Add pasta and roasted butternut squash, if using, and fold until well combined.

Add the macaroni and cheese to the buttered baking dish. Melt remaining butter and toss with the parmesan cheese and both breadcrumbs. Season with a pinch of salt. Add breadcrumb mixture to the top of the mac and cheese, sprinkle with paprika and bake for about 45 mins or until golden brown and bubbly.

I also made this without the roux and tossed the pasta with just 3 1/2 cups of cheese and the squash, added about a 1/4 cup of milk to the casserole, and topped with bread crumb mix. It was not as rich and gooey but better for the waistline.

Roasted Butternut Squash
3 cups butternut squash cubes (about 1 inch in size)
2 tbsp olive oil
}Salt and freshly ground black pepper

Directions

Preheat the oven to 400˚F. Add the butternut squash to a parchment lined baking sheet. Add olive oil and salt and pepper and toss to coat. Roast for about 25 – 30 minutes or until tender.