Preheat oven to 425 degrees F. In bowl toss squash in oil; place in oiled 15x10x1-inch baking pan. Roast, uncovered, 30 minutes, until lightly browned and tender, stirring twice.
Meanwhile, in Dutch oven cook noodles according to package directions. Drain; set aside. In same Dutch oven melt 2 tablespoons of the butter. Add shallots; cook and stir over medium heat for 3 to 5 minutes, until shallots are tender and butter just begins to brown. Stir in lemon juice.
Add noodles and squash to shallot mixture. Stir in mascarpone, 1/2 cup of the Parmesan, 1/4 cup parsley, and 1/4 teaspoon each salt and black pepper. Transfer to greased 2-quart oval gratin dish or baking dish.
n small saucepan melt remaining 2 tablespoons butter; stir in bread crumbs, remaining Parmesan, and parsley. Sprinkle on noodle mixture. Bake, uncovered, 10 minutes, until crumbs are golden.