Butternut Squash Baked Paccheri

To prepare the casserole, preheat an oven to 400°F (200°C). Grease a 9-by-13-inch (23-by-33-cm) baking dish with olive oil; set aside.

In a large bowl, toss together the butternut squash, onion, garlic, olive oil, 2 tsp. salt and a few grinds of pepper. Spread in an even layer on a rimmed baking sheet. Roast until the squash is browned on the edges and fork-tender, about 45 minutes.

While the squash is roasting, bring a large pot two-thirds full of salted water to a boil over high heat. Add the pasta and cook, stirring occasionally, until very al dente, about 2 minutes less than the packaging instructions. Drain, then rinse with cold water to keep the pasta from overcooking. Set aside.

Transfer the squash mixture to a blender. (Leave the oven on.) Add the broth and blend on high speed until smooth, about 1 minute. Transfer the mixture to a pot and place over medium-low heat. Add 2 cups (8 oz./250 g) of the Parmesan, the cream, butter and nutmeg and cook, stirring frequently, until the cheese and butter are melted and the mixture is thoroughly combined. Season with salt and pepper to taste.

Add the pasta to the sauce and stir to coat. Transfer the mixture to the prepared baking dish. Sprinkle evenly with the remaining 1/4 cup (1 oz./30 g) Parmesan. Cover with a lightly greased sheet of aluminum foil.

Bake for 20 minutes, then increase the oven temperature to 425°F (220°C). Remove the foil and continue baking until the top of the mixture is golden brown and the edges are bubbling, about 15 minutes.

While the pasta is baking, make the topping: In a nonstick fry pan over medium-high heat, melt the butter. Add the hazelnuts and cook, stirring frequently, until golden brown and fragrant, 2 to 3 minutes. Transfer the nuts to a paper towel–lined plate and sprinkle lightly with salt.

Wipe out the fry pan with a paper towel and add the oil to the pan. Heat over medium heat until the oil begins to shimmer. Carefully add a few of the sage leaves to the hot oil (be careful, as the oil may splatter) and fry, turning once, until the sage is slightly darkened and lightly crisp, about 15 seconds per side. Transfer the sage to the paper towel–lined plate with the nuts and sprinkle lightly with salt. Repeat to fry the remaining sage.

Remove the pasta from the oven, transfer to a wire rack and let cool for 10 minutes. Sprinkle with more grated Parmesan and a few generous grinds of pepper. Sprinkle the hazelnuts and sage evenly on top and serve immediately. Serves 6 to 8.

Williams Sonoma Test Kitchen