In a skillet over medium high heat, cook ground beef and chopped onion until meat is no longer pink. Drain and place meat in a large mixing bowl. Add corn, soup, noodles, sour cream, salt and pepper and mix thoroughly.
Place into a 13x9 inch baking dish and smooth evenly. Dot top of casserole with butter and sprinkle with breadcrumbs. Bake in preheated oven for 30 minutes until hot and bubbly. Makes 4-6 servings. Enjoy!