This hearty pasta casserole is loaded with flavor from roasted butternut squash and a velvety, dairy-free sauce, all finished with a golden, crunchy breadcrumb topping. It’s comforting, easy to make, and guaranteed to have everyone coming back for seconds.
Cut a medium butternut squash in half lengthwise. Scoop out the seeds and place both halves, cut side down, on a parchment-lined or lightly oiled baking sheet. Roast for 35–45 minutes, or until the wide (bulb) end is completely tender and can be easily pierced with a fork, but is not mushy. The narrow (neck) end should be tender but still hold its shape.
Let the squash cool until safe to handle. Gently remove the tough skin, so only the tender squash remains. Chop into cubes and set aside. You should get about 3 - 4 cups total.
While the squash is roasting, cook the pasta according to package directions, then drain and transfer to a large mixing bowl. Set aside.
Heat 1 tablespoon olive oil in a large skillet over medium heat. Add 1 large finely chopped onion and sauté until golden and soft, about 8–10 minutes. Scoop out about ¼ cup of the cooked onion and set it aside to mix into the casserole later. The rest will go into the sauce.
Heat half of the oil in a medium skillet. Add the onion cook until golden. Transfer to a food processor or blender, leaving about ½ cup’s worth aside for topping.
Blend the Sauce. In a blender or food processor, approximately ⅔ of the cubed squash, the remaining sauteed onion, silken tofu, nondairy milk, nutritional yeast, paprika, salt and pepper. Blend until completely smooth. The sauce should be velvety and pourable; add a splash more milk if needed.
In a large mixing bowl, combine the cooked pasta, remaining squash cubes, and the reserved ¼ cup of sautéed onion. Pour the creamy squash sauce over everything and stir gently to coat.
Transfer the mixture to a lightly oiled 2-quart casserole dish. Sprinkle the breadcrumbs over the top. Add a sprinkle of paprika and a drizzle of olive oil, if desired.
Bake uncovered at 400°F for 20–25 minutes, or until the top is golden and the edges are bubbling. For extra crispiness, broil for the last 2–3 minutes, watching closely.
Let the casserole sit for 5–10 minutes after baking. Garnish with parsley, if desired. This helps it set up and makes it easier to serve. Slice, scoop, and enjoy warm!