This is a very old recipe, from Aunt Susan's newspaper food column. My husband's grandmother made it for him often, it is his favorite cake. There is an uncooked, beaten egg yolk in the frosting. Research on the internet indicates it adds richness to the frosting. I don't know how the frosting would change if it were omitted, I have always used it and it has never caused a problem.
1Using electric mixer on medium high speed, cream butter and sugar until light and fluffy.
2Add 4 beaten egg yolks and continue beating.
3Sift flour, salt and cocoa together.
4Dissolve baking soda in buttermilk.
5Add dry ingredients alternately with buttermilk mixture to the creamed mixture, beginning and ending with dry ingredients.
6Blend in coffee and vanilla.
7Beat egg whites until stiff, but not dry and fold into batter.
8Pour into three greased and floured 8-inch cake pans.
9Bake in 375° oven for 25 minutes.
10Frost with Caramel Cream Icing between layers, sides and top.
11For caramel cream icing:
12Sift cocoa and confectioner's sugar together.
13In mixer, cream butter and sugar/cocoa mixture together thoroughly.
14Add egg yolk, coffee and vanilla. Beat until soft and fluffy. Frost cake.
15NOTE: There is an uncooked, beaten egg yolk in the frosting. I have always used it and it has never caused a problem, however, if you are concerned, internet research gave suggestions of
1)just leave it out, may change texture and richness of frosting
2)substitute pasteurized egg product and use 1/2 the amount listed for 1 egg
3) pasteurize your own egg yolk by heating the egg, whisking constantly, until it reaches 160º. Done over hot simmering water it won't cook solid but will kill bacteria.
4) use reconstituted powdered egg
I HAVE NEVER TRIED ANY OF THESE ALTERNATIVES AND DON'T KNOW WHAT THE FINAL RESULT WOULD BE.