Fill a large pot with water, add a generous pinch of salt, and bring to a rolling boil. While heating, prepare your ingredients: peel and thinly slice the garlic, and tear the basil leaves into smaller pieces.
Add the spaghetti to the boiling water and cook until just shy of al dente, about 8 minutes. Stir occasionally to prevent sticking, and listen for a gentle bubbling sound.
Meanwhile, heat the olive oil in a wide skillet over medium heat. Once shimmering, add the sliced garlic and cook, stirring frequently, until fragrant and lightly golden, about 1-2 minutes.
Add the diced tomatoes to the skillet. Cook, stirring occasionally, until they burst and the sauce begins to thicken and become vibrant, about 10 minutes. The aroma of ripe tomatoes and garlic will fill the air.
Once the pasta is ready, reserve a cup of the starchy pasta water and drain the noodles. Add the drained spaghetti directly into the skillet with the simmered tomato sauce.
Toss the pasta in the sauce over low heat, adding a splash of the reserved pasta water if needed to loosen the sauce. Stir gently until the spaghetti is coated and glossy, about 1-2 minutes.
Remove from heat and tear fresh basil leaves into the dish, tossing gently to release their aroma and add a burst of color and flavor. Finish with a crack of black pepper and a final drizzle of olive oil if desired.
Serve immediately, enjoying the vibrant colors, fragrant aroma, and perfectly cooked pasta. This dish is best enjoyed fresh for maximum flavor and freshness.
