Butter and flour one 8x12 inch baking pan. Preheat oven to 350 degrees F (175 degrees C).
In a pot of lightly salted water, boil squash and onion until tender. Drain well.
In a mixing bowl, combine squash, eggs, mayonnaise, onion, bell pepper and cheese. Place into baking pans, sprinkle with bread crumbs, bake for 30 minutes.