Butternut Squash Baked Pasta

Preheat oven to 350°. Toast hazelnuts on a rimmed baking sheet or quarter sheet pan, tossing halfway through, until golden brown, 6–8 minutes. Let cool, then finely chop and transfer to a medium bowl. Stir in 2 Tbsp. oil; set aside.

Heat remaining 2 Tbsp. oil in a medium pot over medium-high. Cook onion, stirring occasionally, until golden brown and softened, 8–10 minutes. Add garlic and red pepper and cook, stirring, until fragrant and garlic is softened, about 1 minute. Add squash and toss to combine. Add stock and bring to a boil. Reduce heat to medium-low and gently simmer until squash is tender, 12–15 minutes. Let cool slightly.

Meanwhile, cook pasta in a large pot of boiling salted water, stirring occasionally, until very al dente, about 3 minutes less than package directions. Drain, then rinse with cold water.

Transfer squash mixture to a blender. Add 1 cup Parmesan and purée until smooth; season with salt.

Pour ½ cup squash purée into a 13x9" baking dish and spread to edges. Scatter pasta over sauce, then pour remaining sauce over. Top with ½ cup Parmesan. Cover with foil and bake 15 minutes. Uncover and increase oven temperature to 425°. Continue to bake until top is darkened in spots and sauce is bubbling, 10–15 minutes.

Add basil to bowl with reserved hazelnuts, season with salt, and toss to combine. Spoon hazelnut mixture over pasta. Top with more Parmesan and black pepper.