The recipe comes from Jewish American Cookbook written by Regina Frishwasser copyright in 1946. Mrs. Frishwasser was the Food Editor of The Jewish Daily Forward. I produce it verbatim below. I believe fair use for the purposes of review is kosher (yes, I know I made a pun.) My copy is a bit beat up. I got it at a flea market. I think I will research the cookbook and get back to you, Friendly Reader. Back: I can find only one copy for sale in the UK after a quick Google. Back when I learn more.
Egg Cream Cake
Cream 1/2 cup butter with two cups brown sugar and four egg yolks. Add 2 cups flour sifted with two teaspoons baking powder, alternating with one cup sour cream. Add 2 teaspoons cinnamon, 1 teaspoon vanilla, stiffly beaten egg whites, mixing thoroughly. Pour dough into a pan that has been lined with wax paper. Bake in a moderate oven 45 minutes.
This recipe is terse. I am going to assume a "moderate oven" means 350 degrees. I will report back with my experience after the holiday. Mrs. Frishwasser, you are on.
Happy Easter! Happy Spring!