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