Bring a small pot of salted water to a boil. Add 2 ounces of pasta and cook until al dente. Before draining, reserve 2 tablespoons of the pasta water. Drain the pasta and set aside.
Return the pot to the stove over medium heat. Add the butter and let it melt. Stir in the minced garlic and cook for about 1 minute, stirring frequently, until fragrant.
Remove the pot from the heat. Add the cooked pasta and reserved pasta water. Stir until the noodles are evenly coated in the butter.
Stir in freshly grated Parmesan cheese. Season with salt and black pepper to taste.
Transfer the buttered noodles to a bowl. Top with additional Parmesan cheese, if desired, and serve warm.
Notes
Use the Right Pot: A small pot that gives the pasta room to move helps it cook evenly. A 2-quart saucepan works well for a single serving.
Salt the Water: Add 1/4 to 1/2 teaspoon of salt to the boiling water to season the pasta as it cooks.
Start With a Rolling Boil: Always add pasta to fully boiling water to prevent sticking and uneven cooking.
Stir Early: Stir the pasta right after adding it to the pot, then occasionally as it cooks, to keep the noodles from clumping.
Do Not Rinse: Draining is enough. Rinsing removes the starch that helps the butter and cheese cling to the pasta.