Mocha Chiffon Cake

Came across this lovely chiffon recipe in Cherry Potato's blog quite sometime back.  Baked this cake before but haven't posted it.  This time, I'm baking it for my mother in-law.  Hope she likes it.  I didn't get to take photos of the sliced cake cos' I gave her the whole cake.
Here, I used a different mixing method, the cake turns out well cos' the yolk mixture consistency is much better.  A lot easier than using a hand whisk and of course, less labourious [the machine does it all].  The cake is spongy, soft and moist.
Ingredients for Yolk Mixture

20 gm cocoa powder [I used 1 tbsp]
1 tbsp instant coffee

50 ml hot water                     

•   Dissolve cocoa powder and coffee granules in hot water.  Leave to cool

4 egg yolks                           

3 tbsp castor sugar

4 tbsp corn oil
1 tbsp rum [optional]

80 gm plain flour - sifted with 1/4 tsp baking powder

Ingredients for Egg White

4 egg whites

1/4 tsp cream of tartar

4 tbsp castor sugar

1. Preheat oven at 170 degrees C.
2. Place all the dry ingredients [sifted flour and sugar] in the mixing bowl.  Make a well in the centre.  Pour in all the liquid ingredients [mocha mixture, oil, rum and egg yolks].  Beat together using a paddle hook on medium to high speed until well combined and mixture is smooth [takes about 5 minutes].  My new way to mix  yolk mixture. Set aside.
3. Put egg white in another cake mixer bowl [make sure bowl is clean and ungreased].  Whisk egg whites until a little frothy, add in cream of tartar, continue whisking until foamy and add in sugar in 3 batches [I used Kenwood mixer Speed 5].  Keep whisking egg white mixture till soft to stiff peaks formed [process is quite fast].
4. Fold in 1/3 of meringue to egg yolk mixture. Mix evenly till well combined. Then pour into balance egg meringue.  Fold till evenly combined.  Pour batter into 7 inch ungreased chiffon pan.  Smooth the top with a spatula.  Tap pan on table top several times to release trapped air bubbles.
5. Baked in preheat oven at 170 degrees C [lower rack] for 40 minutes. 
6. Invert baked cake immediately to cool completely before removing from pan.