Preheat oven to 350°. Grease bottom of 13 x 9" baking dish.
Cook pasta according to directions in salted water, then drain.
In the pot you cooked the pasta in, heat milk and cream cheese over medium heat. Cook until cheese melted, stirring occasionally. Add the pasta and stir. Spread pasta in baking dish.
Meanwhile, cook ground beef and onion in large skillet. Salt and pepper to taste. Drain excess fat. Add spaghetti sauce and oregano, simmer for 5 minutes.
Pour meat sauce over pasta. Sprinkle mozzarella cheese evenly over top.
Cover and bake for 25 minutes. Uncover and bake 5 minutes. Enjoy!
Notes
Freezes well in tightly sealed container for 3 months.