In a large pot, bring salted water to a boil and cook the elbow macaroni according to the package instructions until al dente. Drain and set aside.
In a separate saucepan, steam the diced butternut squash until tender, about 10-12 minutes. Once done, transfer it to a blender or food processor and blend until smooth. Set aside.
In the same saucepan, melt the butter over medium heat. Once melted, whisk in the flour and cook for about 1 minute until it becomes a light roux.
Gradually whisk in the milk until smooth and bring the mixture to a simmer, allowing it to thicken, about 2-3 minutes.
Add the garlic powder, onion powder, salt, black pepper, and nutmeg to the sauce. Stir in the butternut squash puree until well combined.
Remove the sauce from the heat and mix in the cheddar and mozzarella cheeses until melted and creamy.
Combine the cooked macaroni with the butternut squash cheese sauce, mixing until the pasta is fully coated.
If desired, transfer the mac and cheese to a greased baking dish. Sprinkle breadcrumbs on top for a crispy finish.
Bake in the oven for 20-25 minutes, or until the top is golden brown and bubbly.
Once out of the oven, let it cool for a few minutes, then garnish with chopped parsley before serving.
Notes
Breadcrumbs are optional for topping.
Keyword butternut squash, comfort food, mac and cheese