PASSION FRUIT COCOA COTTONY CAKE [OGURA CAKE]

I'm so addicted to baking this kind of cake [btw this cake is aka Xiang Si, Ogura or Souffle cake] but I am naming it as cottony cake so as not to confuse myself.  The ingredients and methods are practically the same, it's just a twist [change and combine] of flavours.

This time, I'm not posting all the photos on the various steps to make this cake as I've been doing so for almost all my previous posts.
Ingredients for Egg Yolk Mixture

[use 8" square tin]
65 gm superfine flour - sifted

1/4 tsp salt

5 egg yolks

1 whole egg

45 ml corn oil [3 tbsp]

80 ml  passion fruit juice with seeds [obtained from about 2-3 passion fruits]

1. Place the dry ingredients in the mixing bowl and make well in the centre.  Add in eggs, corn oil and passion fruit juice.  Using a paddle hook, beat ingredients until creamy and well combined.   Set aside. 
2. Pour 1 and 1/2 cups water into baking tray, place baking rack on the tray and  preheat oven at 160 degrees C for 10 minutes.

Ingredients for Egg White Mixture

5 egg whites

1/2 tsp cream of tartar

65 gm castor sugar

1 tbsp cocoa powder dissolve with 1 1/2 tbsp hot water - make into paste

1. Using an electric mixer, whisk egg white until frothy, add in cream of tartar and whisk until  slightly foamy.  Add in sugar in 3 batches.  Whisk until soft to stiff peaks formed.
2. Using a spatula, fold in 1/2 of the meringue into egg yolk mixture.  Lift and fold until well combined, then add to rest of meringue.  Fold again until well mix.
3. Remove 1/3 portion of batter, add in cocoa paste.  Mix well.
4. Pour 1/2 of the plain passion fruit batter into a 8" square tin [line base with baking paper at the bottom only].   Add in the cocoa batter, spread batter evenly over passion fruit batter, then add in the remaining plain batter [you can swirl batter with a skewer for marble effect]. 
5. Smooth the surface with a spatula and steam bake in oven at 160 degrees C for 70 minutes.  [Note: for the water bath, use 1 and 1/2 cups water for the duration of baking.  This way the cake base will be dry after baking].
6. Invert the cake after baking  and let it cool slightly [about 10-15 minutes] before removing the pan and baking paper [there maybe some vapour on the baking paper].
7. Cool cake before slicing to serve or refrigerate for serving later.