Bring a pot of salted water to a boil. Cook pasta until al dente. Reserve ½ cup of pasta water, then drain.
In a large skillet, melt the butter with olive oil over medium heat. Stir in the lemon zest and juice. Let it bubble for 1 minute.
Add the cream and stir to blend into a smooth sauce.
Lower heat and gradually stir in Parmesan until melted. Season with salt and pepper.
Toss in the pasta and a splash of reserved pasta water. Stir until coated and glossy.
Garnish with extra Parmesan, herbs, or chili flakes before serving.
Notes
For a lighter version, skip the cream and use more olive oil with pasta water. Meyer lemons offer a slightly sweeter flavor. Add cooked shrimp or chicken for a protein boost, or stir in greens like spinach for added nutrition.