Bring a large pot of lightly salted water to a boil. Add pasta and cook for 8 to 10 minutes or until al dente; drain. Preheat oven to 350 degrees F (175 degrees C).
In a skillet, cook beef until brown over medium heat. Drain excess fat from meat.
Add spaghetti sauce and rotini pasta to browned beef. In a three quart casserole dish layer meat mixture, followed with the mozzarella cheese, repeat.
