I have been reading Ratio, by Michael Ruhlman. I confess that it is my favorite cookery book ever. It is not a recipe book. Instead, it has ratios. Not one recipe, but all the recipes in the whole universe... provided that one can remember the correct ratio.
In the "Batters" section, the first part is entitled "Pound and Sponge Cake." Both of these follow the same ingredients in the exact same proportions; the only thing that varies is the order in which the ingredients are mixed.
A pound cake is mixed using the creaming method (butter and sugar are creamed together, followed by the other ingredients), while a sponge cake uses the foaming method (the eggs and sugar are mixed together, then the rest of the ingredients).
Naturally, I had to experiment with the order of the ingredients... It was unavoidable. The results were revealing. Of course, Ruhlman is right, but what was amazing is the difference that the order in which ingredients are mixed can make.
In my picture, there are two versions of the pound cake: the one in the far left has no rising agents. The cake in the far right is the sponge cake. One of the most interesting things was that the sponge cake rises much more evenly and looks better than the pound cake (which ends up being a more rustic version).