In a large pot, bring salted water to a rolling boil. Add the spaghetti and cook it according to the package instructions until it's al dente, typically around 8-10 minutes. Before draining, reserve about 1 cup of the pasta water for later use, then drain the spaghetti in a colander.
In a large skillet set over medium heat, pour in the extra virgin olive oil and add the sliced garlic. Cook gently, stirring frequently, until the garlic turns golden brown and releases its fragrant aroma, about 3-4 minutes. Be cautious not to let it burn.
Add the red pepper flakes to the skillet with the garlic oil. Stir for about 30 seconds, allowing the heat from the flakes to infuse the oil.
Once the spaghetti is drained, immediately add it to the skillet with the garlic-infused oil. Toss it gently to ensure the pasta is evenly coated.
Sprinkle in the lemon zest, drizzle the lemon juice, and add the chopped parsley to the skillet. Toss everything together thoroughly. If the pasta appears dry, gradually add some of the reserved pasta water until the desired consistency is achieved.
Taste the pasta and season with salt as needed. Give everything a final toss to ensure all ingredients are well mixed.
Plate the spaghetti immediately while it’s hot. If desired, garnish each serving with freshly shaved Parmesan cheese and an optional sprinkle of lime zest.
Notes
Adjust red pepper flakes to taste for heat preference. Optional lime zest adds a refreshing twist.