Purple Sweet Potato Chiffon Cake

Came across this chiffon cake on several blogs and managed to find a Pumpkin Chiffon Cake recipe using 3 eggs.  I substituted the pumpkin with purple sweet potato [can use any other coloured sweet potatoes].  Here are the ingredients.

Ingredients for Egg Yolk Mixture

3 egg yolks

1-2 tbsp castor sugar

1/4 tsp salt

2 tbsp oil

60 gm purple sweet potato [skinned, steamed and mashed]

60 ml coconut milk or fresh milk

• Whisk egg yolks with sugar and salt till creamy, then drizzle in oil.  Continue whisking for awhile then drizzle in coconut milk/fresh milk.  Lastly stir in mashed sweet potato.   Fold in the flour and diced potatoes until well combined.  Set aside while you whisk the egg white.  Preheat oven at 170 degrees.

70 gm cake flour sifted together with 1/2 tsp baking powder

100 gm purple sweet potato cubes [diced and steam for 15 minutes] - set aside to cool

Ingredients for Egg White Mixture

3 egg white

3 tbsp sugar or 50 gm

1/4 tsp cream of tartar

• Whisk egg white till frothy then add in cream of tartar.  Continue whisking till foamy then gradually add in sugar.  Whisk till soft peaks formed.
• Fold in 1/3 portion of meringue into egg yolk mixture till well combined.  Then fold mixture into balance meringue till well incorporated.  Add in sweet potato cubes. 
• Pour batter into 7" chiffon pan and bake in preheated oven at 170 degrees for 40 minutes.
• Invert pan immediately after baking to cool cake before removing from pan.