In a large pot or deep skillet, heat olive oil over medium heat.
Add the sliced onion and cook for 3-4 minutes until softened.
Add the minced garlic and cook for 1 minute until fragrant.
Add the dried penne pasta, zucchini slices, cherry tomatoes, vegetable broth, diced tomatoes with juice, dried oregano, dried basil, red pepper flakes, salt, and black pepper to the pot.
Stir everything together to combine.
Bring the mixture to a boil over medium-high heat.
Once boiling, reduce heat to medium-low and simmer uncovered, stirring frequently, for about 12-15 minutes or until the pasta is cooked and most of the liquid is absorbed.
Remove the pot from heat and stir in the grated Parmesan cheese until melted and well combined.
Sprinkle chopped fresh basil over the pasta before serving.