Peel squash; slice crosswise into 1/2-inch slices. (If using butternut squash, first cut the squash in half lengthwise.) Remove and discard seeds from squash. Set squash aside.
Cook onion rings in the 1 tablespoon hot butter for 5 to 10 minutes or until tender.
Arrange half of the squash slices in the bottom of an 8x8x2-inch baking dish. Top with half of the pear slices. Repeat layers. Sprinkle lightly with salt. Cover with the cooked onions.
Bake, covered, in a 350 degree F oven about 45 minutes or until nearly tender.
Meanwhile, in a small bowl combine bread crumbs, bacon, walnuts, Romano cheese, and the 1 tablespoon melted butter; sprinkle over vegetables. Bake, uncovered, about 15 minutes more or until squash is tender. If desired, sprinkle with parsley.