Sponge Cake - F.A.I.L

I got this recipe and the feedback were great so I decided to give it a try:

http://hubpages.com/hub/Sponge-Cake-Recipe

The modifications I did were cut the recipe in half and made muffin-sized sponge cake instead of a whole cake.

I did not have cake flour so I tried substituting with one cup all purpose flour minus 2 tablespoons all purpose flour plus 2 tablespoons potato starch since I did not have corn starch. The recipe failed. The sponge cake was okay right after out of the oven but turned so hard after 4 hours. Like cookies!

I also tried substituting cake flour with 2/3 cups all purpose flour and 1/3 cup potato starch. Also failed. The sponge cake was very crunchy and the center did not look fully cooked.

I finally stopped by the supermarket to buy cake flour, and plus I was also out of butter, milk and eggs. I followed the recipe but omitted the lemon since I forgot to buy lemon (and eggs. Arghhhh). When I was doing the final blending, my food processor broke! (Grrrrrr!). I can tell you how it broke but that will be another story.

So in the end, I only mixed the batter for about 5 minutes. They looked light and fluffy so I just started baking. 30 minutes later, top golden brown but center uncooked. 35 minutes later, center still look uncooked even though there are no more traces of flour. 45 minutes later, I officially got a batch of muffin-sized cookies.

Disappointing day.

I did take some pictures. They look okay, and edible, just not what I expected.

Note: The reason why uncooked inside was the temperature too high; the outside was baked too fast and burnt before the inside was baked . Since the recipe is for a whole cake, I should lower the baking temperature for my muffin-sized sponge cake. I don't know if I should lower the temperature to half of the recipe and bake for 1.5 times as long.

Cake baking is more complicated than baking muffins and cookies. So many different kinds of cake, flour, and mixing procedure. But I will tackle this, one step at a time, until end of this month.

PS I am suddenly craving Malaysian cake (also known as ma lai go, those steamed cake you find at dim sum restaurants). I will try making this tomorrow :D