Marble Chiffon Cake (6.5")

I'm in mood of baking chiffon cakes lately....especially when you have your dearest lil ones asking to bake more....All my chiffon cakes I baked yesterday had gone into their stomach, especially Ally ate most of my Pandan chiffon cake & both gals bring to school this morning. So, I bake another different chiffon cake called Chocolate Marble Chiffon but this one instead of using cream of tartar for egg whites, it calls for cornflour....mmmm...something new for me to learn each day when you bake....I'm curious...anyone know the reason why?

Ingredients:
(A) 50g Cake flour
      1/2 tsp baking powder
      1/16 tsp salt

(B) 2 egg yolks
      15g castor sugar
      25g corn oil
      25g milk/water
      5g cocoa powder

(C) 2 egg whites
      50g castor sugar
      5g cornflour

Directions:

1. Beat ingredients (B) then add ingredients (A).  Mix well until a smooth batter.
2. Beat egg whites with bubble whisk until slightly foamy, add cornflour & beat until frosty.  Add sugar tbsp by tbsp & beat until stiff peak foam & mixture does not slide out of mixing bowl when upturned.
3. Add in 1/3 of the beaten egg whites into the yolk mixture & fold in gently to prevent the batter from deflating.  Do not overfold.
4. Pour batter into the mold.  Run a spatula through the batter to eliminate large bubbles in the batter.
5. Bake at the preheated oven 165 deg C for about 40-45 mins.