Hot pasta absorbs more sauce
Behind every great pasta is a great sauce. And it's not just the flavor of the sauce that matters, but when and how the sauce and the pasta get combined.
Toss hot pasta with hot sauce quickly—without rinsing it—so the pasta absorbs more sauce and flavor. As it cools, the swollen starch in the pasta crystallizes and becomes insoluble, and the pasta won't absorb as much sauce. Just so there's no delay, I always prepare the sauce first in a large skillet, even if it's simply olive oil, garlic, and pepper flakes. The second the pasta is done (I like it just a breath beyond al dente), I scoop it out of the water with a big Chinese ladle-type strainer or spider. I let the pasta drain over the pot for a few seconds, and then I dump it into the hot sauce, stir well, and set a lid on the skillet. I let the pasta sit, covered, to absorb the sauce for a minute or two, and then I remove the lid, stir again, and serve instantly.