Cake is a form ...

do u know.. 
Cake is a form of bread or bread like food. In its modern forms, it is typically a sweet baked dessert.
Roman and Greek history records cake-making but according to food historians it’s the early Egyptians who were the first skilled bakers. Cakes were called "plakous" by the Greeks, from the word for "flat." These cakes were usually combinations of nuts and honey. They also had a cake called "satura," which was a flat heavy cake. During the Roman period, the name for cake became "placenta." They were also called "libum" by the Romans, and were primarily used as an offering to their gods.
No wonder the first cakes bore a strong similarity to bread.
Even today, at any special event, there is likely to be a cake of some sort involved in the Celebration.
Today there are thousands of cakes recipes (some are bread-like and some rich and elaborate) and many are centuries old. 
The most primitive peoples in the world began making cakes shortly after they discovered flour. By the early 19th century, due to the Industrial Revolution, baking ingredients became more affordable and readily available.
There are five basic types of cake, depending on the substance used for leavening. i. e Cakes are based primarily on ingredients and cooking techniques.
Yeast cakes are the oldest and are very similar to yeast breads.
Cheesecake is a sweet dish consisting primarily of a mixture of soft, fresh cheese (not always cream cheese), eggs, and sugar; often on a crust or base made from crushed cookies or graham crackers, pastry or sponge cake. 
Butter cakes primarily use baking powder or baking soda for height. Sponge cakes depend on the air trapped in the eggs during beating. Sponge cakes trap air generally of beaten eggs to provide leavening, sometimes with a bit of baking powder or other chemical leaven added.
Butter cakes, including the pound cake and devil's food cake, are a combination of butter, eggs, and sometimes baking powder or bicarbonate of soda to provide both lift and a moist texture.
Food fact . . .
Why are cakes round?
The round cakes we know today descended from ancient bread. Ancient breads and cakes were made by hand. They were typically fashioned into round balls and baked on hearthstones or in low, shallow pans. These products naturally relaxed into rounded shapes. 
A Useful Tip Before mixing the cake batter, soften the butter so that it mixes easily with the sugar.
The biggest development of baking powder made the ability to make a cake something that could be done without advance preparation required by yeast cakes. The ease of cake baking increased the opportunities to celebrate with cake.