Bring 6 cups of water to a rolling boil in a large pot. Add 1 tablespoon kosher salt. Stir in 1 lb penne and cook uncovered, stirring occasionally, until al dente according to package instructions (usually 10–12 minutes). Reserve 1 cup of pasta cooking water, then drain the pasta and set aside.

Marinara Sauce

Sweat aromatics

While the pasta cooks, heat 2 tablespoons extra-virgin olive oil in a large sauté pan or medium saucepan over medium heat. Add 1 cup finely diced yellow onion and a pinch of salt; cook, stirring occasionally, until the onion is soft and translucent, about 5–7 minutes. Add 4 minced garlic cloves and cook 30–45 seconds until fragrant, taking care not to brown the garlic.

Develop sauce base

Stir in 2 tablespoons tomato paste and cook 1–2 minutes, stirring frequently, to slightly caramelize and deepen flavor.

Add tomatoes and seasonings

Add one 28 oz can crushed tomatoes to the pan. Stir to combine, then add 1 teaspoon dried oregano, 1 teaspoon dried basil, 1 teaspoon red pepper flakes, 1 teaspoon sugar (optional), 1 teaspoon salt, and 1 teaspoon freshly ground black pepper. Bring the mixture to a gentle simmer over medium-low heat.

Simmer and reduce

Allow the sauce to simmer gently, uncovered, for 15–20 minutes, stirring occasionally, until it thickens slightly and the flavors meld. Taste and adjust salt, pepper, or sugar as needed. If sauce becomes too thick, stir in up to 1/2 cup of the reserved pasta cooking water to reach desired consistency.

Finish sauce with fresh herbs

Remove the sauce from heat and stir in 1 cup torn fresh basil leaves (optional) and a drizzle (about 1 teaspoon) of extra-virgin olive oil for gloss and flavor.

Combine & Serve

Toss pasta with sauce

Add the drained penne to the pan with the marinara sauce (if your pan is too small, return pasta to the pot and pour sauce over it). Toss gently over low heat for 1–2 minutes to coat the pasta, adding reserved pasta water a tablespoon at a time if needed to help the sauce cling.

Plate and garnish

Divide the pasta among 4 plates. Sprinkle each serving with about 1/4 cup (approximately 1 ounce) grated Parmesan cheese and 1/2 tablespoon chopped fresh parsley, if using. Add additional torn basil leaves on top if desired and finish with an extra light drizzle of olive oil.