In a large pot, fill with water, add a generous pinch of salt and bring it to a rolling boil. Carefully add the fettuccine or spaghetti to the boiling water and cook according to the package instructions until al dente, usually about 8-10 minutes. Before draining, reserve 1/2 cup of the pasta water to adjust the sauce later. Once cooked, drain the pasta and set aside.
Heat a large skillet over medium-high heat and pour in the olive oil. As the oil heats, add the peeled and deveined shrimp, seasoning them liberally with salt, pepper, and red pepper flakes if you desire a bit of heat. Cook for 2-3 minutes on each side until the shrimp turn pink and opaque. Once done, carefully remove the shrimp from the skillet and transfer them to a plate; set aside.
In the same skillet where the shrimp were cooked, lower the heat to medium. Add the minced garlic and sauté for about 1 minute, stirring constantly until fragrant but not allowing it to brown.
Pour the heavy cream into the skillet and gently stir to combine it with the garlic. Let the mixture simmer for 2-3 minutes until it begins to thicken. Gradually whisk in the grated Parmesan cheese, continuing to stir until the cheese melts completely and the sauce turns creamy and smooth. If it becomes too thick, slowly incorporate some of the reserved pasta water until you achieve your preferred consistency.
Add the sautéed shrimp back into the skillet, tossing them to coat in the creamy sauce. Next, introduce the cooked pasta along with the lemon zest, gently mixing everything together until the pasta is evenly coated with the creamy mixture. Taste the dish and adjust seasoning with more salt and pepper if necessary.
Portion the creamy garlic shrimp pasta into bowls, finishing each serving with a sprinkle of freshly chopped parsley for a pop of color and flavor. Add more grated Parmesan on top if desired for an extra cheesy touch.
Notes
Adjust the red pepper flakes based on your heat preference.