Prepare your chiffon pan. Do not grease it. Line the pan with a parchment paper only at the bottom. Line the outer part with aluminum foil. Have another bigger pan ready for water bath.
Put egg yolks, coconut oil, pumpkin puree, milk, cake flour into a bowl. Whisk altogether until well incorporated. Set aside.
Beat egg white with sugar. While beating with slow speed, put in the sugar in three parts. Egg white will gradually rise up. Put in salt and ¼ tsp cream of tartar or 1 teaspoon of lemon juice. Turn up the speed to medium. Keep beating until soft peak.
Take 1/3 of the meringue, add to the egg yolk mixture. Use a whisk to mix the batter evenly. Continue adding the meringue to the mixture until finished. Gently fold the meringue and the batter until no trace of meringue is seen in the batter.
Pour the batter into the pan. Use another pan as a tray to pour in hot water. Put the pan with the batter in the center.
Bake 150°C in water bath method for 65 minutes with the bottom heat. Put in the middle rack. Use upper heat to bake the top part for 5 minutes afterwards.
Take out from the oven and let it cool completely (Image 10). Slide out the cake from the pan when it has cooled down. Enjoy!
Video
Notes
Use food processor the puree the steamed pumpkin. Sieve it to get a smooth texture.
Make sure you do not grease the chiffon baking pan. Only line with parchment paper on the bottom. Line the outer part of the pan with aluminium foil so water does not seep in.
Using water bath technique will make the cake moist and easy to take off from the pan. Just wait until it is cool enough, you can use a thin knife to slit the sides of the cake.