Bring a large pot of salted water to a rolling boil, then add the spaghetti. Cook until just al dente, about 8 to 10 minutes, stirring occasionally. Reserve a cup of pasta water, then drain the noodles and set aside.
While the pasta cooks, heat the olive oil in a large skillet over medium heat. Add the sliced garlic and sauté until fragrant and lightly golden, about 30 seconds to 1 minute, releasing a warm, nutty aroma.
Add the halved or quartered tomatoes to the skillet. Cook gently, mashing them slightly with the back of a wooden spoon, until they soften and release their juices, about 3 to 5 minutes. The mixture should become fragrant and slightly thickened, with vibrant red color.
Season the sauce with sea salt and freshly cracked black pepper, tasting and adjusting as needed. Toss in the torn basil leaves, letting their aroma infuse the sauce for about a minute.
Add the drained spaghetti directly into the skillet. Using tongs, toss the noodles with the sauce to coat evenly, allowing them to absorb the flavors for 1 to 2 minutes over low heat. If the sauce seems thick, stir in a splash of reserved pasta water for a glossy finish.
Finish with a drizzle of olive oil, a few whole basil leaves for garnish, and an extra crack of black pepper. Serve immediately while hot, enjoying the vibrant aroma and lively flavors.
