A foam cake is a cake that has no fat added and uses mostly egg whites. This will be your healthiest option for cake. there is no chemical or outside source used to leaven, instead it is leavened by beating air into the egg whites.
To Mix a foam cake you need to sift and measure the flour then beat only egg whites until they have a foamy consistency. Next, you add salt and cream of tarter then beat until stiff peaks. Then, add sugar and beat until stiff peaks, then fold in the flour mixture.
Sift to get a light and fluffy consistency.
Most important step is separating the yolk from the egg white, without this, the stiff peaks cant form because there is still fat in the mixture. Make sure not to get any in!!!
This highlights the key step of beating air into your egg whites. It needs to be whisked until stiff peaks form, by combining sugar and the whites.
Angle Food Cake Recipe http://allrecipes.com/recipe/15432/angel-food-cake-iii/?internalSource=hub%20recipe&referringContentType=search%20results&clickId=cardslot%203
This video shows step by step how to prepare an Angle Food Cake and uses the same method that our classroom uses.
I got the recipe from Allrecipes.com and the video from Youtube.com