The name of that white powder is baking powder, which makes the breads and cakes soft and fluffy.
The main ingredients of a cake or a bread is :Baking powder, baking soda, salt, sugar, yeast and the most important, 'Flour'.
.Baking powder and yeast :They make the cakes and bread soft and fluffy.
Salt and sugar :They should be added in a adequate amount as they the main ingredient for taste in a cake.
Flour:It are the most important ingredient, as without it , making a cake is impossible.
bake ur cake nicely :p , hoped helped u :))