Heat the olive oil in a large skillet or Dutch oven over medium-high heat.
Add the onion, carrots, and celery. Cook for 5 to 6 minutes until softened.
Stir in the garlic and cook for 30 seconds.
Add the ground beef and cook until browned, breaking it into small crumbles as it cooks. Drain excess grease if needed.
Mix in the tomato paste and cook for 2 minutes.
Pour in the crushed tomatoes, diced tomatoes, and beef broth.
Add the Italian seasoning, oregano, basil, paprika, salt, pepper, and sugar if using.
Bring the sauce to a gentle simmer and cook uncovered for 30 to 40 minutes, stirring occasionally.
Meanwhile, cook the rigatoni in salted boiling water until al dente according to the package directions.
Reserve ½ cup of pasta water before draining.
Add the cooked rigatoni to the sauce and toss until evenly coated. Stir in a splash of reserved pasta water if needed to loosen the sauce.
Serve immediately with freshly grated Parmesan cheese and chopped parsley.