Heat the olive oil in a large pot or deep skillet over medium-high heat.
Add the ground beef and cook, breaking it up with a spoon, until browned and cooked through, about 5-7 minutes.
Add the diced onion and cook until softened, about 3 minutes.
Stir in the minced garlic, dried oregano, dried basil, crushed red pepper flakes, salt, and black pepper. Cook for 1 minute until fragrant.
Pour in the diced tomatoes with their juice and the beef broth. Stir to combine.
Add the uncooked penne pasta to the pot and stir to submerge the pasta in the liquid.
Bring the mixture to a boil, then reduce heat to medium-low and simmer uncovered, stirring occasionally, until the pasta is tender and most of the liquid is absorbed, about 15 minutes.
Remove the pot from heat and stir in the grated Parmesan cheese until melted and well combined.
Sprinkle chopped fresh parsley over the top and serve immediately.