Cook the pasta in salted water according to package directions.

Over medium heat, melt 4 tablespoons of butter in a saucepan. Add the cream and simmer for 4-5 minutes, until just thickened. Whisk in the parmesan cheese and stir continuously until cheese has melted. Season with salt and pepper and a pinch of cayenne pepper.

Melt remaining 1 tablespoon of butter in a skillet over medium-high heat. Add the shrimp to and season with salt and pepper. Cook for 3-4 minutes, stirring occasionally, until shrimp are opaque. Add the garlic to the pan and cook for another 30 seconds.

Drain the pasta and toss with the alfredo sauce. Place the shrimp on top, garnish with parsley and serve immediately.