While the pasta cooks, heat the olive oil in a large skillet over medium heat. Add the smashed garlic cloves and cook for 1 to 2 minutes, stirring occasionally, until fragrant and lightly golden in spots.

Add the cherry tomatoes along with a generous pinch of kosher salt. Reduce the heat to medium-low and cook for 10 to 15 minutes, stirring occasionally, until many of the tomatoes have softened, blistered, and begun to burst. The tomatoes should slowly cook down and caramelize, creating a glossy sauce. Keep the heat gentle enough to prevent the oil from splattering too aggressively, but not so low that the tomatoes stop cooking down and caramelizing.

As the tomatoes cook down, carefully use the back of a spoon to gently press some of them to help create the sauce while leaving others whole. Be careful, as the hot tomato juices may splatter. If the skillet starts to look dry, add 2 to 3 Tablespoons of reserved pasta water at a time as needed to keep the sauce glossy and saucy.

Add the cooked spaghetti directly to the skillet and toss well to coat. Continue tossing, adding additional pasta water a little at a time as needed, until the sauce becomes glossy and lightly coats the pasta.