Cook pasta according to package instructions. Drain and set aside.
Grate parmesan cheese and set aside, to allow it to come to room temperature.
Heat a large sauce pan over medium heat. Add butter and cook until melted. Add garlic, stirring frequently for 1 minute. Add cream and whisk to combine, bring to a simmer and cook for 3-4 minutes, stirring often.
Turn heat to low and add parmesan cheese, whisking until smooth. Season with salt and pepper to taste. Add pasta and toss to coat.
Season shrimp with salt and pepper. Melt 1 tablespoon butter or oil in a large skillet over medium high heat. Add shrimp and cook, stirring occasionally, until pink, about 2-3 minutes. Serve noodles with a scoop of shrimp on top. Garnish with fresh parsley, if desired.
Parmesan Cheese: Avoid using pre-shredded parmesan as it won't melt as smoothly or taste as good as freshly grated! Healthier Alfredo Sauce: You could use milk or half and half; the sauce wont be as creamy, and you may want to thicken it with a cornstarch slurry. Or substitute this healthy alfredo sauce from my One-Pan Skinny Chicken AlfredoSeafood Alfredo: Add Seared Scallops to make this a heavenly seafood alfredo!Chicken and Shrimp Alfredo: Toss in some grilled chicken!Shrimp Alfredo with Broccoli: Add some steamed broccoli or other favorite vegetable at the end, right before serving.Cajun Shrimp Alfredo: Season shrimp with cajun seasoning before cooking. Add 1 teaspoon cayenne pepper to alfredo sauce (or less, if you don't want it spicy).