Bring a large pot of salted water to a boil. Add spaghetti or fettuccine and cook according to package instructions, usually around 8-10 minutes, until al dente. Reserve a cup of pasta water for later use, drain, and set aside.

In a large skillet, melt 2 tablespoons of unsalted butter over medium-high heat. Add the shrimp, seasoning lightly with salt and pepper. Sauté for about 2-3 minutes until shrimp are pink and opaque. Remove and set aside.

In the same skillet, lower the heat to medium and add another tablespoon of butter. Add minced garlic, sautéing for about 1-2 minutes until fragrant. Pour in heavy cream and simmer, stirring frequently for 3-5 minutes.

Stir the cooked shrimp back into the sauce, adding grated Parmesan cheese until melted and creamy. If too thick, add reserved pasta water.

Toss the drained pasta with the sauce and shrimp until completely coated. Add a sprinkle of salt and cracked pepper.

Squeeze lemon juice over the dish. Serve warm, garnished with extra Parmesan and fresh herbs if desired.