Bring a large pot of salted water to a boil. Add the elbow macaroni and cook according to package instructions until al dente. Drain and set aside.
In a skillet over medium heat, add the ground beef. Cook until browned, breaking it apart with a wooden spoon, about 5-7 minutes.
Add the diced onion and minced garlic to the skillet with the beef and cook until the onion is translucent, about 3-4 minutes.
Stir in the ketchup, beef broth, Worcestershire sauce, and mustard powder. Allow the mixture to simmer for about 5 minutes, stirring occasionally.
Add the cooked macaroni into the skillet and mix until well combined. Season with salt and pepper to taste.
Remove the skillet from heat and stir in the shredded cheddar and mozzarella cheese until melted and creamy.
Serve the Cheesy Sloppy Cheeseburger Pasta hot, garnished with chopped parsley if desired.