Boil the pasta: Bring a large pot of salted water to a boil. Cook pasta until just al dente.
Reserve 1/2 cup of the pasta water, then drain.
Season the shrimp: Pat shrimp dry. Season with salt, pepper, and a pinch of red pepper flakes if using.
Sear the shrimp: Heat olive oil in a large skillet over medium-high. Add shrimp in a single layer and cook 1–2 minutes per side until just pink.
Transfer to a plate.
Sauté garlic: Reduce heat to medium. Add butter, then garlic. Cook 30–60 seconds until fragrant, not browned.
Deglaze with wine: Pour in the white wine.
Simmer 2–3 minutes, scraping up any browned bits, until slightly reduced.
Add cream and lemon: Stir in heavy cream, lemon zest, and 1–2 tablespoons lemon juice. Simmer gently 2–3 minutes until lightly thickened.
Add Parmesan: Whisk in Parmesan until melted and smooth. Taste and adjust salt, pepper, and lemon juice.
The flavor should be bright but balanced.
Combine: Add cooked pasta and shrimp to the skillet. Toss gently, adding splashes of reserved pasta water as needed to create a silky, glossy sauce.
Finish: Stir in parsley. Serve immediately with extra Parmesan and a final squeeze of lemon if you like.