This is not an expensive meal to make, but it tastes as if you really went all out. The versatile Alfredo sauce can also be used for my Red-and-White Mostaccilo (p.73) as a pizza sauce, and as a dipping sauce for homemade bread sticks (p.233). To make a leaner Alfredo, substitute half-and-half or fat-free evaporated milk for the heavy cream and reduce or omit the cream cheese;the result will be a thinner sauce. Vary the ratio of pasta to sauce as desired.
Melt the butter in a medium saucepan over low heat. Mix in the cream cheese. Stir in the cream and garlic powder. Increase the heat and bring to a boil. Decrease the heat and simmer, stirring often, while you cook the pasta. If the sauce needs additional thickening (for example if your're serving it as a dipping sauce with pasta), you may sprinkle in flour, 1 teaspoon at a time. Cook and stir for desired consistency.
Cook the fettuccine according to package directions; drain.
Stir the Parmesan cheese into the sauce and season with salt and pepper to taste.
Toss the sauce and the pasta in a large bowl and serve immediately.
Serve with a tossed green salad and hot French bread or bread sticks.