Coffee Golden Sponge Cake

The Chocolate Golden Sponge Cake that I made the previous night was so well received and yummy, I need to make another one tonight because it was all wiped out by the next day! :)

Tonight, it's coffee flavor!😋

Ingredients

*yields a 6" cake

50g butter 

50g cake flour

1tsp coffee powder

1tsp coffee oil (acts as flavor enhancer, can omit if don't have)

3 egg yolks

55g milk

3 egg whites (A size)

50g caster sugar

6g corn starch

Method

1. Preheat oven at 140C.
2. Prepare a cake pan with removable base, don’t need to grease or line with baking paper.  Do not use a non-stick pan.  Wrap with aluminium foil as the cake will be baked by waterbath.
3. Sieve the cake flour and coffee powder together,  Set aside.
4. Melt butter in a saucepan, once it melted and simmers, immediately add in the sieved ingredients (in #3) and quickly stir well to combine. 
5. Transfer the mixture to a bigger mixing bowl and add in milk & coffee oil.  Using a hand whisk, mix well to a smooth batter.  Then add in the egg yolks, 1 by 1, mixing well with each addition.  Set aside.
6. Mix sugar and corn starch together. 
7. Beat egg whites until foamy, then add in sugar and corn starch mixture gradually and continue beating until the whites reach soft peaks (meringue stand straight up with a little curve at the tip).
8. Using a hand whisk, mix the meringue into the yolk mixture via 3 batches.  Fold in the last batch with a spatula.  Fold until you do not see any meringue in the batter.
   *Note: the batter is more runny than the usual cake batter
9. Pour the batter into cake tin, from a high height (say, 30cm from baking tin), then tap the tin few times on the table top.  This will help to release the air bubbles in the mixture.
10. Send to bake at 140C for 25mins, then at 160C for another 25mins.
11. Once baked, remove the cake from the oven immediately and drop the tin from a high height(say 30cm).  This will help to prevent shrinkage. 
12. Invert the cake to cool completely before removing it from the tin via hand un-moulding method (just like how you would remove a chiffon cake).  If you want a smooth surface, you can invert on a non-stick frying pan/cookie tray.

Important tips for this recipe:

1. Bake it over low temperature first then increase higher temperature, and always bake it at the lower rack. 

2. You need to have stable meringue; soft peaks (meringue stand straight up with a little curve at the tip).