Bring a large pot of salted water to a boil. Add the penne pasta and cook according to package instructions until al dente, about 10-12 minutes. Drain and set aside.
While the pasta cooks, heat the olive oil in a large skillet over medium-high heat.
Add the ground beef to the skillet and cook, breaking it apart with a spoon, until browned and cooked through, about 6-8 minutes. Drain excess fat if necessary.
Add the chopped onion to the skillet with the beef and cook until softened, about 4 minutes.
Stir in the minced garlic and cook for 1 minute until fragrant.
Add the crushed tomatoes, tomato paste, dried oregano, dried basil, salt, black pepper, red pepper flakes, and beef broth to the skillet. Stir to combine.
Bring the sauce to a simmer, reduce heat to low, and cook uncovered for 15 minutes, stirring occasionally.
Add the cooked pasta to the skillet with the sauce and toss to coat evenly.
Stir in the grated Parmesan cheese and chopped fresh parsley until well combined.
Serve hot with additional Parmesan cheese sprinkled on top.