Acorn Squash Casserole

Preheat oven to 425°F with rack in upper third of oven. Line a large baking sheet with foil. Place squash halves, cut-side up, on the prepared baking sheet; brush with oil. Roast until tender, about 40 minutes. Let stand until cool enough to handle, about 10 minutes. Reduce oven temperature to 350°F.

Scoop the squash flesh into a large bowl. Mash with a potato masher or a large fork until smooth. Add milk, eggs, shallot, garlic, 1/3 cup Parmesan, 1/2 teaspoon salt and 1/4 teaspoon pepper; stir until well combined. Pour the mixture into a lightly greased 7-by-11-inch baking dish.

Combine breadcrumbs, butter, parsley, sage, rosemary and the remaining 1/3 cup Parmesan and 1/4 teaspoon each salt and pepper in a medium bowl. Sprinkle the breadcrumb mixture in an even layer over the squash mixture. Bake until set, 28 to 30 minutes. Switch oven to broil; broil the casserole until the topping is golden brown, 1 to 3 minutes.