While the pasta is cooking, prepare the garlic butter sauce. Peel and thinly slice the garlic cloves. In a large skillet, melt 2 tablespoons of butter over medium heat. Once the butter is melted and begins to foam slightly, add the sliced garlic. Sauté for 1-2 minutes, stirring constantly, until the garlic is fragrant and just barely beginning to turn golden at the edges. If it starts browning too quickly, reduce the heat immediately. Add the pepper and stir for 10 seconds.

The moment your pasta is drained, immediately transfer it to the skillet with the garlic butter. The pasta should be hot when it hits the pan. Add about ⅓ to ½ cup of the reserved pasta water to the skillet. Using kitchen tongs or two forks, start tossing the pasta vigorously over medium heat. Keep tossing for 1-2 minutes – you'll notice the liquid beginning to thicken and cling to the pasta. Add the remaining 2 tablespoons of butter and continue tossing until the butter melts and is incorporated into the sauce.

Remove the skillet from the heat. Add the freshly grated Parmesan cheese in two or three additions, tossing continuously between each addition. The residual heat will melt the cheese while the tossing motion incorporates it into the sauce, making it creamier. Add the chopped fresh parsley and toss again. Taste the pasta and adjust the seasoning with salt if needed. Add black pepper to taste.

Give the pasta one final toss. The consistency should be creamy and glossy, coating each strand without being watery or dry. If it seems thick, add a bit of pasta water and toss. Serve immediately in warmed bowls or on a pasta plate.