In a large pot of boiling salted water, cook the rigatoni according to package instructions until al dente. Drain the pasta, reserving about 1 cup of the pasta water, and set aside.
In a large skillet over medium heat, add the olive oil. Once hot, add the chopped onion and sauté until soft and translucent, about 4-5 minutes. Add the minced garlic and cook for an additional 1 minute, until fragrant.
Pour in the crushed tomatoes, and stir to combine. Add the dried basil, dried oregano, and red pepper flakes (if using). Bring to a simmer and let it cook for 10-15 minutes, stirring occasionally. Season with salt and pepper to taste.
Add the cooked rigatoni to the sauce, tossing to combine. If the sauce is too thick, gradually add reserved pasta water until you achieve desired consistency. Cook together for 2-3 minutes to allow the flavors to blend.
Remove from heat and transfer to serving bowls. Garnish with fresh basil leaves and a generous sprinkle of grated Parmesan cheese.
Notes
Feel free to adjust the spice level by adding more or less red pepper flakes.