Bring a large pot of heavily salted water to a boil. Add 1 pound penne and cook until just al dente according to package directions. Before draining, reserve 1/2 cup pasta water. Drain the pasta and set aside (do not rinse).

While the pasta cooks, heat 1/4 cup extra virgin olive oil in a large saucepan, braiser, or Dutch oven over medium-high heat until shimmering.

If using fresh onion: add 1/2 yellow onion, diced, and sauté 5–7 minutes until softened. If using 1 teaspoon onion powder instead of fresh onion, do not sauté onion now—you will add the onion powder later with the tomatoes.

Add 6–8 cloves minced garlic and 1–3 teaspoons crushed red pepper flakes (start with less and increase to taste). Sauté for 1 minute, stirring so the garlic does not brown.

Add 2 tablespoons tomato paste and cook, stirring, for 1 minute.

Add the entire 128 oz can San Marzano whole tomatoes with juices, 1 teaspoon dried oregano, 1/2 teaspoon dried thyme, and 1/2 teaspoon salt. If you are using onion powder, add the 1 teaspoon now. Break up the whole tomatoes with a potato masher or wooden spoon until the sauce reaches your preferred texture.

Bring the sauce to a vigorous simmer, then reduce heat to maintain a gentle simmer. Cook uncovered for 15–20 minutes, stirring occasionally and mashing tomatoes as needed. If the sauce becomes too thick, add a few tablespoons of the reserved pasta water to thin it.

Stir in 3 tablespoons minced fresh basil (or 1 tablespoon dried) and 2 tablespoons minced fresh parsley (or 2 teaspoons dried).

Add the drained penne to the sauce and toss gently to coat, adding more reserved pasta water a tablespoon at a time if needed to achieve the desired consistency. Cook together 1–2 minutes so the pasta absorbs the sauce.

Taste and adjust heat by adding more crushed red pepper flakes if desired, and add additional salt only if needed. Serve immediately with plenty of freshly grated Pecorino Romano or Parmesan cheese.