Cook the noodles according to the package directions. Drain and set aside.

In a nonstick skillet, brown the meat and the onion. Add the tomato sauce and oregano. Taste and adjust the seasonings, if desired.

Combine the cream cheese, sour cream, cottage cheese, scallions, salt, and pepper.

Preheat the oven to 350 degrees F. To assemble the casserole, grease a 9-inch by 13-inch baking dish. Layer half the noodles, all the cream cheese mixture, the remaining noodles, and the meat sauce. Top with the Parmesan cheese, if desired. Bake for 20 to 30 minutes. Serve hot.