Cook macaroni noodles according to package directions and drain.
In a large bowl combine sour cream, cheddar cheese and cottage cheese. Add cooked noodles to this and mix well.
Transfer to a lightly buttered (or butter sprayed) 9x13 dish.
Sprinkle parmesan cheese, breadcrumbs or a combination of both on top. Bake in a 350 degree oven for 35 minutes or until the top is lightly browned.
If topping with cheese or breadcrumbs you may add a small amount of milk to the 2nd step depending on how creamy you prefer your macaroni and cheese. I have even added stewed tomatoes from time to time.
You can even double this recipe by simply remembering that for every 8 or 16 ounces of macaroni you use, you will also use the same amount of cheddar and cottage cheeses as well as sour cream. Your baking time will also increase.