Good Housekeeping and Giada De Laurentiis both have good recipes for ravioli cream sauce, but each recipes is quite different. The Good Housekeeping version is a light cream sauce, and the Giada De Laurentiis version is a creamy tomato sauce.
For the Good Housekeeping version, prepare the ravioli as stated on the label, drain, and keep warm. In a saucepan, heat 1 tablespoon of oil, and cook a small onion until tender. Stir in 1 1/2 teaspoons of flour, cook for 1 minute, and then gradually stir in a cup of 1 percent milk. Stir constantly until the mixture begins to boil and thicken. At this point, remove the saucepan, stir in 2 tablespoons of Parmesan cheese, and spoon it over the ravioli before sprinkling the pasta with 1/4 cup of prosciutto and parsley leaves.
To make the Giada De Laurentiis recipe, prepare spinach ravioli, and toss it in a bit of oil. Bring 1 cup of marinara sauce to a simmer, and then whisk in 1/2 cup of ricotta and water until the sauce has a good consistency. Season the sauce with pepper and salt, and then spoon the sauce over the bottom of a bowl before arranging the ravioli on the plate. Drizzle more sauce over the top of the ravioli, sprinkle with Parmesan cheese, and garnish with basil.