In a large pot, bring water to a boil. Add 2 tablespoons of kosher salt and cook the pasta according to the package instructions. Before draining, reserve 1 1/2 cups of the pasta cooking water for later use.

While the pasta cooks, heat the olive oil over medium heat in a large sauté pan or shallow pot. Add the sliced garlic and sauté for approximately 2 minutes, stirring often until the garlic just begins to turn golden—be careful not to overcook it. Stir in the crushed red pepper flakes and cook for an additional 30 seconds. Carefully add the reserved pasta water, bring the mixture to a boil, then reduce the heat. Allow the sauce to simmer for about 5 minutes until it has reduced by a third.

Add the drained pasta to the garlic-infused oil and toss to combine. Off the heat, mix in the parsley and grated Parmesan cheese. Toss thoroughly to ensure even coating. Allow the pasta to sit for 5 minutes so the sauce can be fully absorbed. Taste for seasoning and serve with extra Parmesan on the side.