Cook the fettuccine pasta according to package instructions in a large pot of boiling salted water for about 8-10 minutes. Drain and reserve a cup of pasta water.

In a large skillet, melt 4 tablespoons of unsalted butter over medium heat for 1-2 minutes until it foams.

Whisk in 1/4 cup of all-purpose flour until smooth and cook for about one minute to create a roux.

Gradually pour in 2 cups of whole milk while whisking. Cook over medium heat for 3-5 minutes until it thickens slightly.

Stir in 4 ounces of cream cheese until melted and well combined. Cook for another 2 minutes.

Add 1 cup of freshly grated Parmesan cheese, 1 teaspoon garlic powder, 1/2 teaspoon onion powder, and salt and pepper to taste, stirring until melted.

Gently fold in 8 ounces of fresh crabmeat, heating for 2-3 minutes without breaking it apart.

Add the cooked fettuccine to the skillet and toss until thoroughly coated with the sauce. If too thick, add reserved pasta water.

Serve immediately, garnishing with chopped fresh parsley.