Preheat oven to 350°F.
In a large skillet, over medium heat, brown the ground beef along with the diced onion.
Add the chili powder, ground cumin, cayenne pepper, garlic powder, onion powder, salt, and pepper to the ground beef.
Pour in the water and make sure the seasoning is well mixed in and dissolved.
In a small bowl, combine the corn starch and 2 tablespoons water. Add it to the skillet.
Add the refried beans, chili beans, and tomato paste to the skillet. Keep stirring until the refried beans and tomato paste have become smooth and everything is well combined.
Slowly add 2 cups of the shredded cheese to the skillet. Keep folding in the cheese until it has all melted.
Reduce heat to medium-low. Let the mixture simmer for about 10 minutes, stirring frequently so nothing sticks and burns on the bottom.
Add one cup of the beef mixture to the bottom of a 9x13-inch baking dish.
Fill the cooked noodles with the mixture by holding one end of the noodle closed and stuffing the open end until filled. Place in the baking dish.
Top with any leftover mixture and the rest of the cheddar cheese.
Bake for 15-20 minutes, or until bubbly.
Top with sour cream and onion (optional).