Bring a large pot of salted water to a rolling boil over high heat. Add the fettuccine and cook until al dente, about 8-10 minutes. Reserve ½ cup of the pasta water before draining the fettuccine.

In a large skillet, heat 2 tablespoons of olive oil over medium heat. Add the shrimp, seasoning them with salt, pepper, and optional red pepper flakes. Cook for 2-3 minutes on each side until pink and opaque. Remove from skillet and set aside.

In the same skillet, add minced garlic and sauté for about 1 minute. Pour in 1 cup of heavy cream, bringing it to a gentle simmer. Cook for 2-3 minutes while stirring frequently.

Gradually whisk in 1 cup of Parmesan cheese into the cream. Continue whisking until the sauce is smooth. If too thick, add reserved pasta water to reach desired consistency. Taste and season with salt and pepper.

Add cooked fettuccine and shrimp back into the skillet with the sauce. Toss to coat everything in the creamy sauce, heating it for a couple of minutes until warmed through.

Transfer to serving plates and sprinkle with chopped fresh parsley. Serve immediately while hot.