Heat oven to 375°F. Cook pasta according to package directions. Meanwhile, cut meatballs in half.
Combine marinara sauce and meatballs in a large skillet; bring to a boil over high heat.
Reduce heat to medium-low; stir well, cover and simmer 5 to 6 minutes or until meatballs are heated through, stirring once.
Stir in drained pasta; mix well.
Transfer half of mixture to an 8 or 9-inch baking dish; top with 1 cup of the cheese. Repeat layering with remaining pasta mixture and cheese.
Bake 20 to 25 minutes or until heated through and cheese is melted.