Do you use baking powder and soda with cake flour?

Baking powder is a dry chemical leavening agent used to increase the volume and lighten the texture of baked goods such as muffins, cakes, scones and American-style biscuits. Baking powder works by releasing carbon dioxide gas into a batter or dough through an acid-base reaction, causing bubbles in the wet mixture to expand and thus leavening the mixture.

hmmm, and in non-wikipedia terms, basically it helps the cake to rise, and usually you add a pinch of salt to the mix, because it makes the baking powder taste less soapy :D hope this helps!