Greetings, Mary. I'm posting this recipe that I pulled off the internet years ago. I make it often and particularly like it on chocolate cake. It is soft and fluffy and surprisingly like whipped cream in texture. The author noted that if you want absolutely white frosting you should use shortening in place of butter. However, we don't eat hydrogenated products in our house so we always use butter instead, even though the frosting comes out ivory rather than white. At the bottom of the page there was this credit:

A World of Baking by Dolores Casella (David White, 1968), p. 88

Cooked Cream Frosting

1 cup milk
1/4 cup all-purpose flour
1/2 pound unsalted butter, at room temperature
1 cup (or more to taste) sifted confectioner's sugar
1 1/2 teaspoons vanilla (or grated lemon rind)

Combine the milk and flour and blend until smooth (a blender works great for this). Transfer to a saucepan and cook over low heat, stirring all the time, until thick and bubbly. Do not allow the mixture to brown. Set aside, cover with plastic wrap or waxed paper (right on the surface of the mixture in order to prevent a skin from forming) and refrigerate until cool.

Using an electric mixer, cream the butter until light and fluffy. Add the cooled mixture and blend thoroughly. Gradually beat in the sugar and flavoring. Continue to beat until of spreading consistency, about 10 to 15 minutes.

Makes enough to frost two 9-inch rounds.

[My own note: I often add a tiny pinch of salt to peak up the flavor of this frosting. Also, I have found that most frosting recipes seem a little skimpy, so I sometimes increase this recipe by 1/4 to 1/2, depending on how large my cake is.]

Enjoy!

Marilyn