This recipe is very loosely adapted from a Martha Stewart dish. It’s a good way to incorporate vegetables into this dairy-and-pasta favorite.

Steps

1. Preheat the oven to 400 degrees.
2. Place the squash on a baking sheet (slice them in half and oil the cut sides, if you like) and roast until soft, about 45 minutes to 1 hour depending on the size and density of the squash. When done, remove from the oven and set aside until cool enough to handle.
3. Meanwhile, bring a large pot of water to a boil and cook the pasta until al dente, about 8 to 10 minutes. Drain and return to the cooking pot; toss with a little olive oil to keep the pasta from clumping together.
4. Remove the seeds and stringy pulp from the centers of the squash halves and discard (or save the seeds for toasting). Scoop out the squash flesh and place in a large bowl. With your fingers or a potato masher, mash the squash into an even purée.
5. Preheat the oven to 375 degrees.
6. And the mustard, garlic, cayenne, nutmeg, salt and pepper, and flour to the squash and mix well. Add the cheeses and milk and mix well. Add the pasta and toss until the pasta is evenly coated with the squash mixture.
7. Lightly oil a 9-by-13-inch baking dish. Spread the pasta mixture evenly in the dish.
8. Melt the butter in a small saucepan and toss with the breadcrumbs. Sprinkle the buttered breadcrumbs evenly across the top of the pasta, then grate a thin layer of fresh Parmesan atop the breadcrumbs.
9. Bake until bubbly and browned on top, about 30 minutes. Let cool briefly before serving.