
In a large pot over medium heat, bring about 4 quarts salted water to a boil. Add macaroni and cook 1 to 2 minutes less than package's directions. Rinse under cold running water and drain well.
In a pot over medium heat, heat oil. Add sliced hotdogs and cook, stirring occasionally, for about 1 to 2 minutes or until lightly browned. Remove from pan and set aside.
Add onions and garlic and cook until softened.
Add bell peppers and cook until tender-crisp.
Add ground beef and cook, stirring occasionally and breaking apart with the back of a spoon, for about 7 to 10 minutes until lightly browned. Drain any excess fat.
Add tomato sauce, tomato paste, ketchup, and beef broth.
Stir in sugar and Italian seasoning.
Bring to a boil. Lower heat, cover and continue to cook for about one hour or until meat is fully cooked and sauce is thickened.
During the last 10 minutes of cooking, add browned hotdogs. Season with salt and pepper to taste.
In a skillet over medium heat, melt butter.
Add flour and stir well into a smooth paste. Cook, stirring regularly, for about 5 to 7 minutes or until golden (but NOT browned) and starts to bubble a bit.
Gradually add milk to the roux, whisking vigorously to prevent lumps. Cook, whisking regularly, for about 2 to 3 minutes or until smooth and thick enough to coat the back of the spoon.
Stir in nutmeg and salt and pepper to taste.
Gradually add quick-melt and cheddar cheese, whisking regularly until melted. Cook until cheese sauce is thick but spreadable.
Grease bottom and sides of a 9 x 13 baking dish with nonstick cooking spray and set aside.
In a large bowl, combine macaroni and meat sauce. Gently toss together until well-combined.
Transfer the pasta mixture to the prepared dish. Spoon cheese sauce on top, spreading across to cover the pasta completely.
Bake in a 375 oven for about 20 to 25 minutes or until hot and bubbly. Remove from oven and allow to cool for about 15 minutes before cutting into serving portions.