Step 1

Cook the spaghetti according to package directions. Reserve 1 cup of pasta water then drain the spaghetti.

Step 2

Meanwhile, add the butter and oil to a large Dutch oven and heat over medium heat. Add the onion and cook for 5 minutes until the onion softens. Add the garlic and cook for another 30 seconds until fragrant.

Step 3

Add the tomatoes, salt, pepper, sugar and red pepper flakes. Cook for about 5 minutes until the tomato starts to break down, stirring occasionally. Reduce heat to simmer and cook for 15 minutes. Taste for seasoning and adjust as necessary.

Step 4

Stir in the basil. Add the cooked spaghetti and half of the pasta water. Toss everything well to combine. Add more pasta water if needed.

Step 5

Serve topped with Parmesan cheese and more basil.