Bring a large pot of water to a rolling boil over high heat. Add ½ tablespoon of salt. Add the fettuccine and cook for 8-10 minutes, stirring occasionally, until al dente (tender but still with a slight bite in the center). Check the package directions for exact timing.

Before draining, reserve 4 tablespoons (about ¼ cup) of the starchy pasta water—this is crucial for creating the perfect sauce consistency. Drain the pasta in a colander, but do not rinse it.

While the pasta cooks, heat a large skillet over low heat. Add the butter and finely chopped garlic and cook gently for 1-2 minutes, stirring frequently, until fragrant but not browned. Keep the heat low to prevent burning the butter or garlic.

Pour the heavy cream into the pan with the butter and garlic. Increase the heat to medium and cook for 2-3 minutes, stirring occasionally, until it thickens slightly.

Reduce the heat back to low. Add the freshly grated Parmesan cheese and keep stirring until the cheese melts completely and the sauce becomes smooth, creamy, and glossy. This should take about 1-2 minutes.

Add 2 tablespoons of the reserved pasta water to the sauce along with salt and pepper and stir to combine—this helps the sauce become silky and helps it cling to the pasta.

Add the drained fettuccine to the pan and toss everything together using tongs, lifting and turning the pasta until every strand is evenly coated with the creamy Alfredo sauce. If the sauce seems too thick, add the remaining pasta water, one tablespoon at a time, until you reach your desired consistency.

Taste the pasta and adjust the seasoning as needed. Remember, Parmesan is salty, so you may need less salt than you think. Toss once more, then remove from heat immediately. Serve hot in bowls or on plates, with extra grated Parmesan and black pepper on top if desired.