Preheat oven to 350˚ F.
Cook the egg noodles according to package directions. Drain and set aside.
Brown and cook the ground beef with the diced onions. Drain the fat.
Add the garlic, salt, sugar, and tomato sauce. Bring to a simmer. Let simmer for 10 minutes.
In a small bowl, mix the sour cream and cottage cheese.
In a greased 9x13 baking pan, layer half the noodles, half the meat, and half the sour cream mixture. Repeat and top with mozzarella.
Bake for 20-25 minutes in a preheated 350˚ F.
