The center of the cake will rise high as the sides of the cake will be set properly when heated. The sides of the cake will be hot, and the cake will start getting baked from the outside towards the inside. So, the periphery of the cake will be baked first than the center as the heat is absorbed by the peripheral part of the cake quickly. The chemical reaction that occurs in the center will make the cake to raise high at that region. But, at the peripheral parts of the cake, before this chemical reaction occurs, the heat will bake these parts quickly. Therefore, there will not be the chance for the rising to take place. The rising at the center can be prevented by following certain procedures. The batter at the center can be distributed to the sides of the cake and a smaller amount can be made to exist at the center. The temperature of the oven being high can also make the center rise more than the periphery. If the temperature is reduced, the rise at the center can be prevented, but the total time for baking will increase.
The sides of the cake get hardened as they are adjacent to the liners. The expansion of the batter in the cake at the sides is prevented by the lining and they remain flat. The expansion of batter at the center region of the cake will not happen towards the sides and the bottom. The only way its expansion is allowed is towards the top. If the quantity of batter that is used is large, then the top will raise more. If the quantity is less, the rise in the middle will be less. The stirring of the cake contents will allow more air to be stored and help in the rising of the batter. Special flour can be added to the cake to avoid a large mound to occur in the center. But, if the cake is not stirred briskly, or if the flour is not added to it, then the cake will not be fluffy and soft. It may not taste as good. So, the cakes will raise high in the middle.
The cakes rise in the middle as the chemical reaction that is responsible for the fluffiness of that part completes before that part is completely baked. The peripheral region gets baked before the chemical reaction occurs. The rise in the middle is also due to the batter expansion being allowed towards the top as the peripheral or side regions are baked sufficiently to resist the expansion (due to chemical reaction) from the middle region.
Rating: 6.5 May publish after reviewing the following: (Again, the article just leaves the reader hanging with a lack of a summary or facts to tie it all in together. I truly recommend more information written for this article.)