Heat 2 tablespoons extra-virgin olive oil in a large skillet over medium-low heat. Add the finely minced onion and cook, stirring occasionally, until translucent, about 4–5 minutes.

Add both cans of whole plum tomatoes (with their juice) to the skillet and gently crush them with a wooden spoon or spatula. Add 6 fresh basil leaves (torn or roughly chopped), cover the skillet, and simmer on low heat for 15 minutes, stirring occasionally, until the sauce is creamy but still slightly chunky. Season with sea salt and black pepper to taste.

While the sauce simmers, bring a large pot of lightly salted water to a rolling boil. Add the mafaldine pasta and cook according to the package directions; for al dente, cook 2–3 minutes less than the package time. Before draining, scoop out and reserve 2 tablespoons of the pasta cooking water, then drain the pasta.

Remove the tomato sauce from the heat and add the remaining 2 fresh basil leaves (torn or chopped).

If the ricotta cheese is watery, let it drain briefly in a fine-mesh sieve. Add the 8.8 oz ricotta to the sauce along with the reserved 2 tablespoons of pasta cooking water. Stir until the ricotta is incorporated and the sauce is creamy. Taste and adjust seasoning with salt and pepper as needed.

Add the drained mafaldine pasta to the skillet and fold gently to coat the pasta evenly with the sauce. If the sauce seems too thick, add a little more of the reserved pasta water, a teaspoon at a time, until you reach the desired consistency.

Drizzle any remaining olive oil from the skillet over the pasta (if present), give a final gentle toss, and serve immediately.