When I'm at a bookstore, I usually peruse cookbooks, especially those on desserts. I've always wondered what a chiffon cake actually is. Here's an answer from http://bakingbites.com/2010/07/what-is-chiffon-cake/:
"Chiffon cakes are foam cakes, cakes that are leavened primarily with beaten egg whites, just like angel food cakes are. In fact, they are very similar in appearance to angel food cakes and are usually baked in the same type of tube pan. Chiffon cakes, unlike angel food cakes, contain both egg yolks and vegetable oil. These two ingredients keep the cake moist, soft and tender and result in a cake that tastes great and keeps well."
The bakingbites.com entry also mentioned butter cakes. I will look for that next.
After sifting Google here is an image from http://www.hispanickitchen.com/profiles/blogs/orange-chocolate-chiffon-cake