Bring large pot of salted water to boil for pasta.
Melt butter in large skillet over medium heat.
Add garlic and cook 30 seconds until fragrant.
Pour in white wine and simmer 2-3 minutes until reduced by half.
Lower heat to medium-low and stir in heavy cream.
Gradually whisk in parmesan cheese and Cajun seasoning until smooth, 2-3 minutes.
Simmer sauce 2-3 minutes until thickened.
Meanwhile, cook fettuccini 10-12 minutes until al dente.
Season sauce with salt and pepper to taste.
Add cooked pasta to sauce and toss to coat.
Thin with hot pasta water if needed.
Serve topped with parmesan and parsley.