I've achieved sponge cake nirvana. This is a light and moist sponge cake -- so delicious that you won't even notice the lack of butter and flour. It is the perfect Passover dessert.
After my two recent failures, I was especially pleased that this cake was a success. The recipe, handwritten on a page of an old calendar, was given to me by Arthur Schwartz who inherited it from his mother. In addition to the wonderful texture, the cake has a lovely citrus note from the lemon and orange zest and juice.
It's important to begin with room temperature eggs. If you've just arrived home from work and your eggs have been in the fridge all day, no problem. Just place them in a bowl and cover with warm water for a while while you prep the other ingredients.
Chop the nuts (or chocolate) and zest and juice the fruit.
Measure out the cake meal and potato starch.
Beat the yolks for a long time ("beat yolks good" says the recipe) until light in color, then add the sugar and beat the mixture even more until the yolks become very light in color. (Do not let the sugar and eggs sit in the bowl without mixing, for the sugar will "cook" the eggs and you'll end up with small bits of scrambled egg.) Mix in the citrus and the dry ingredients.
The recipe is below. I used about one cup of chopped walnuts. Next time, chocolate! The "cake flour" refers to cake meal, available this time of year.