Cook the shrimp: Add the shrimp to the skillet in a single layer. Let them cook undisturbed for about 2 minutes until pink and slightly golden on one side, then flip and cook another 1-2 minutes.
Create the creamy sauce: Lower the heat to medium-low and pour in the heavy cream. Stir gently to combine with the garlic butter. Sprinkle in the Parmesan cheese and stir until melted and sauce is smooth and slightly thickened, about 3-4 minutes.
Finish with zest and seasoning: Add the lemon juice, and if you want a little heat, sprinkle in some red pepper flakes now. Taste and adjust salt and pepper as needed.
Garnish and serve: Stir in the chopped parsley for a fresh splash of color. Serve immediately while creamy and dreamy!
