2 tablespoons unsalted butter 1 pound short twisted or tubular pasta, such as gemelli, cavatappi, or rotini Kosher salt 2 tablespoons chopped fresh parsley Grated Parmigiano-Reggiano for serving Heat the oil and smashed garlic cloves in a 10-inch skillet over medium-high heat until the cloves are gently sizzling Reduce the heat to medium-low and sizzle until the garlic is golden brown, to minutes Discard the garlic cloves, leaving the oil in the skillet, and return the skillet to high heat Add the sliced garlic and pepper flakes and cook, stirring constantly, until the garlic just begins to turn pale golden brown, about 45 seconds Add the minced garlic and toss until fragrant, about 30 seconds Remove from the heat and stir in the butter Set aside Place the pasta in a large pot and cover with hot water Add a large pinch of salt and bring to a boil over high heat stirring occasionally to keep the pasta from sticking Continue to cook until the pasta is fully softened but retains a slight bite in the center (about 1 minute less than the box recommends after the pasta reaches a boil) Drain the pasta, reserving ½ cup of the cooking liquid, and return to the pot, set over medium-low heat Pour the sauce over the pasta, add half of the reserved pasta water, and stir until the sauce comes together and coats the pasta, about 2 minutes, adding more pasta water as necessary until the desired consistency is reached Stir in the parsley and season to taste with salt Serve immediately, passing Parmesan at table ...in the parsley and season to taste with salt Serve immediately, passing Parmesan at table