Bring a large pot of water to a rolling boil. Add 2 tablespoons salt per 4 quarts water.

While water heats, prepare the tomatoes. Cut a small X on the bottom of each tomato. Drop them into the boiling water for 30-45 seconds, until the skins start to peel. Transfer to a bowl of ice water. Peel, core, and crush the tomatoes by hand into a bowl. Reserve all juices.

In a large skillet, heat olive oil over medium heat. Add garlic and red pepper flakes (if using). Cook for 1 minute until fragrant and garlic is pale gold — do not brown it.

Add the crushed tomatoes and their juices to the skillet. Stir in 1 teaspoon salt. Bring to a gentle simmer, then reduce heat to low. Cook uncovered for 15-18 minutes, stirring occasionally, until the sauce thickens slightly and the oil separates on the surface. Taste and adjust salt.

Meanwhile, cook pasta in the boiling water until al dente, about 1 minute less than package directions. Reserve 1 cup of pasta water before draining.

Drain the pasta and transfer directly to the skillet with the sauce. Add a splash of pasta water (about ¼ cup) and toss over medium heat for 60-90 seconds, until the sauce clings to the pasta. Add more pasta water if needed to loosen.

Remove from heat. Add torn basil and toss gently. Serve immediately with grated Parmigiano-Reggiano on the side.