Heat olive oil in a large skillet over medium-high heat.
Add ground beef and cook, breaking it apart with a spoon, until browned and cooked through, about 5-7 minutes.
Drain excess fat from the skillet if necessary.
Add diced onion to the skillet and cook until softened, about 3 minutes.
Stir in minced garlic, dried oregano, dried basil, salt, black pepper, and crushed red pepper flakes; cook for 1 minute until fragrant.
Pour in the diced tomatoes with their juice and beef broth; stir to combine.
Bring the mixture to a boil, then add the uncooked penne pasta.
Reduce heat to medium-low, cover, and simmer for 15 minutes, stirring occasionally, until the pasta is tender and most of the liquid is absorbed.
Remove the skillet from heat and sprinkle shredded mozzarella and grated Parmesan cheese over the top.
Cover the skillet again and let it sit for 2-3 minutes until the cheese melts.
Garnish with chopped fresh parsley before serving.