Successful sponge cake

I think I have mastered the skill in baking sponge cake. 1 time done collapsed, 2 time done slightly collapsed and this time, didn't collapsed at all.... Yippee!!! I have master it very well... This is really what it called "practice makes prefect." 

Requested by my girl again, she wanted something to bring to school the next day, she actually requested some sponge cupcakes which I baked last week.  I wanted to try again on my pan sponge cake, so I decided to bake a whole sponge cake instead.

Adopted the recipe from "nasilemaklover.blogspot.sg" I tried her vanilla sponge cake.. Here are her ingredient and method...

Vanilla Sponge Cake香草海绵蛋糕

(recipe source: by Sonia aka Nasi Lemak Lover)
*makes a 8”(width) x 3” (height) cake pan with removable bottom

5 egg yolks

25g sugar
1tsp vanilla extract
85g water
65g corn oil
135g Top flour (high ratio flour) or cake flour

5 egg whites

90g sugar
1/2tsp cream of Tartar

Method

1. Prepare one 8” round cake tin (Not a non-stick), Do not need to line paper at all.
2. Immediate separate cold eggs from fridge (easy to separate this way) into two clean mixing bowls. Set aside to return to room temperature.
3. Add in sugar into egg yolks, immediately lightly whisk the egg yolks and sugar till light (Try to whisk immediately once sugar is added into egg yolks, egg will cover the sugar and turned hard if sit there for too long).
4. Add in vanilla extract and corn oil, mix well. Then add in water, stir well to combine.
5. Sift in flour, stir till well combined.
6. Whisk egg whites and cream of tartar till foamy, gradually add in sugar in there batches and continue beat until approaching stiff peaks (meringue stand straight up with a little curve at the tip) or till stiff peaks (this stage is a bit difficult to fold with egg yolk mixture)
7.Take 1/3 of meringue and use a hand whisk to mix well with egg yolk batter.
8.Fold in 1/3 of meringue and use a silicone spatula, gently fold with egg yolk batter till slightly combined. Fold in the balance meringue and gently fold till well combined.
9. Pour into the cake tin, bake at pre-heated oven at 140C (no fan) for 25mins at low rack, then increase to 160C(fan forced) for another 40mins.
10.Once baked, turn your sponge cake upside down and cool completely before remove from the cake pan (Finished cake size is 8” x 2.5”).