Preheat oven to 350 degrees F (175 degrees C). Lightly spray a large, deep casserole dish with cooking spray.
Cook pasta according to package instructions.
While pasta cooks, melt butter in large, heavy-bottomed skillet; add onions and saute for 5 minutes. Add ground beef and cook until no longer pink. Add salt, tomatoes, chili seasoning, and Ragu(R) Old World Style(R) Traditional sauce. Stir to combine and cook over medium-low heat for 5 minutes or until ready to add to pasta.
Drain pasta and return to pot. Stir in corn and 1 1/2 cups of cheese; mix until evenly combined. Stir in the chili. Pour into the casserole dish and top with remaining cheese. Bake until hot and bubbling, about 15 minutes.