Baked Spaghetti

This is my momma's spaghetti pie recipe, and sometimes it just hits the spot.  It's easy and doesn't have a lot of ingredients and produces a lot of leftovers.  Being pregnant has left me without energy, so cooking at night has been a challenge.  This kind of meal is great because it gives another meal for the week, and likely one for the freezer.

6 oz spaghetti (I always use angel hair pasta over spaghetti noodles)
2 Tbsp butter
1 egg, beaten
1/3 cup grated parmesan cheese
1 cup cottage cheese
1 cup shredded mozzarella
1 lb ground beef
1/2 cup chopped onion
15 oz pasta sauce

Cook pasta and drain.  Stir in butter, egg, and parmesan into hot spaghetti.  Form into "crust" in a pie plate.  Brown onions.  Add meat and brown.  Add spaghetti sauce, simmer 25-30 minutes.  Spread cottage cheese over spaghetti crust.  Top with meat sauce.  Bake 30 minutes at 350 degrees.  Top with mozzarella in last 5 minutes of baking time.