Preheat oven to 350°F and grease a 9x13-inch baking dish.
Cook egg noodles according to package directions until al dente, drain, and toss with butter.
In a large skillet over medium-high heat, brown ground beef with diced onion and minced garlic until meat is no longer pink and onions are softened, about 8 minutes.
Drain excess fat and stir in tomato sauce, Italian seasoning, salt, and pepper, then simmer for 5 minutes.
In a separate bowl, combine sour cream, cottage cheese, and 1 cup of shredded mozzarella cheese.
Layer half of the cooked noodles in the prepared baking dish, then spread the cheese mixture over the noodles.
Add the remaining noodles, then top with the beef mixture and sprinkle with remaining 1/2 cup mozzarella cheese.
Bake uncovered for 25-30 minutes until cheese is melted and casserole is heated through.