Mom's Squash Casserole

Cook zucchini and squash in boiling salted water until tender, about 12 to 15 minutes; drain and mash. Add onion, egg, salt, pepper and half the melted butter.

Pour mixture into a greased 13"x9" baking pan. Sprinkle with cracker crumbs; drizzle with remaining butter. Bake, uncovered, at 350° for one hour.