Easy sponge cake

[satimis]

Baked a sponge cake according to following recipe;

Eggless Sponge Cake Recipe
Sponge Cake Recipes and Angel Food Cake Recipes
http://www.razzledazzlerecipes.com/angel-food-cake-recipes/eggless-sponge-cake.htm

Ingredients:-
200 g sweetened condensed milk
130 g self-raising flour
60 ml melted butter (63.4 g used)
1 level tsp baking powder
1/2 tsp baking soda
1 tsp vanilla extract

Preheated Kenwood KM450 bread machine to 320 deg F.

Sieve the flour, baking powder and baking soda together. Mix the ingredients together, add 75ml water and beat well.

Poured the mixture into the baking pan of the bread machine and baked for 20 min. After finish baking the top of the cake was in light yellow colour. Baked it for another 10 min at same temperature to make the top in dark brown colour.

Photo-01 - eggless sponge cake
http://ubuntuone.com/3Mr8kRYk733tnkj297nMp8
Photo-02 - eggless sponge cake slices
http://ubuntuone.com/36bpM4MFDGEL4IXQYEKrKM
Photo-03 - eggless sponge cake with blueberry yoghurt topping
http://ubuntuone.com/6Yom0eeKOagsDTmPXMLLRW

The cake is tender and tasty with good smell because of butter. This is an easy cake with about 15 min for preparation, without heavy beating.

I have following questions:
- can I add more baking powder (or baking soda) to make it more sponge?

- if I need to double the size of the cake whether just doubling the quantity of all ingredients?

Comment and suggestion would be appreciated. TIA

B.R.
satimis

[duonyte]

Normally doubling the ingredients is the way to go, but I do not know if the bake cycle would be long enough. If you can watch the bake time and lengthen if necessary then it might just work.

I don't know whether doubling the baking soda will make it spongier - it might make it more fragile, causing it to collapse. Also, sometimes you can sense a mettalic or other off-taste from baking powder, which also would be a concern.

[satimis]

For bread and cake cycles there are size selection, 500g/750g/1000g. However I can only use "Bake Only" cycle with only time selection availabe on 10 min interval up to 1hr 30 min max. I can't use other cycles because the kneading operation.

The sponge cake sold in bakery is light in weight, seemingly dissolved immediately in month. The homemade sponge cake is chewy although it is tender. I wonder how the bakery make their sponge cake.