Preheat the oven to 325. Lightly mist a baking dish with cooking spray and set it aside.
In a large skillet, brown ground beef. Chop into small crumbles.
While ground beef is browning, cook rotini noodles until done. Drain and set aside.
Once browned, add green pepper (if desired), tomato sauce, and taco seasoning to the ground beef.
In a large bowl, mix rotini noodles, sour cream, and 1/2 cup of shredded cheese.
Place noodle mixture at bottom of baking dish. Pour ground beef mixture on top of noodles. Bake for 25 minutes.
After 25 minutes, remove from oven and add the remaining 1/2 cup of shredded cheese. Bake for another 5-10 minutes until cheese is melted.
