There are four main ingredients in cake 
recipes:  sugar, flour, eggs, and fat (in the form of oil, shortening, 
or butter). These four  ingredients have different purposes and effects 
on how your cake will bake, its texture, and how it will taste.
The structure of your cake is held together
 with the eggs and flour.  The flavor of your cake comes from the sugar 
and the fat.  The more sugar and fat you have in your cake, the more 
moist the cake will be.  However, do not go assuming that simply adding 
more sugar and more fat to your batter will produce a moist cake.  You 
have to maintain an equal amount of δομή to hold up to the extra 
moisture you’re adding in.  Adding too much moisture and too little 
structure and you’ll end up with a cake that won’t set.
 
 
