Bring a large pot of heavily salted water to a rolling boil. Add 1 tbsp olive oil if desired, then add the pasta and cook according to package directions until al dente. Reserve 1 cup of the starchy pasta water before draining.

While the pasta cooks, heat 2 tbsp olive oil in a large skillet or Dutch oven over medium heat. Add the chopped yellow onion and cook until softened and translucent, about 5-7 minutes.

Stir in the minced garlic and cook for another 1 minute until fragrant, being careful not to burn it.

Pour in the crushed tomatoes. Season with 0.5 tsp salt and 0.25 tsp black pepper. Bring to a gentle simmer, then reduce heat to low, cover, and let it cook for at least 15 minutes, stirring occasionally, to allow the flavors to meld.

Remove the lid, stir in the heavy cream and 0.5 cup grated Parmesan cheese. If the sauce is too thick, add a splash of the reserved pasta water until it reaches your desired consistency. Taste and adjust seasoning as needed.

Add the drained pasta to the skillet with the sauce. Toss to combine thoroughly, ensuring every strand is coated. Stir in the 0.25 cup fresh basil. Serve immediately with extra grated Parmesan and fresh basil on top.