Unshortened cakes are also called foam cakes and are typically light and airy from being made with stiffly beaten egg whites. Foam cakes, like angel food cake and sponge cake, are lower in calories than other types of cake because they are not made with egg yolks or butter.
Angel food cake, sponge cake, chiffon, roulade and genoise are all unshortened cakes. Angel cake is usually made in a tube pan and can usually be found for sale at grocery stores and bakeries pre-made. Foam cakes can be used as a lower fat alternative to the standard butter cake, which is the cake typically associated with birthday cakes. Roulade is a delicate sponge cake that is baked flat, rolled and filled with things like Bavarian cream or fruit purees. Genoise is also called French butter sponge cake and is a pliable, light and absorbent cake that is often used as the base for desserts like baked Alaska, petit fours, tiramisu and upside down cakes.
Pound cakes and butter cakes are the opposite of unshortened cakes in richness and density. They are heavier and do not absorb as well as foam cakes. Shortened cakes contain a higher fat content because they are made with egg yolk and butter or other solid fats like shortening.