Add 5 tbsp boiling water to the Yuja (honey citron tea) and stir till diluted. Mince the citron peel with a pair of scissors. Add this into the egg yolk mixture and mix well.
Sieve flour and baking powder together twice and stir well into the egg yolk mixture with a hand whisk.
Beat egg white and cream of tar tar until foamy, slowly add sugar and continue to beat until peak form.
Gently fold beaten egg white foam into egg yolk batter until blended OR Slowly pour all the egg mixture into the meringue at low speed then stop machine. Using a rubber spatula and fold the mixture well.
Pour batter into a 20cm tube pan and bake at 170C for 40-45 minutes.
When cake is done, remove from oven and turn the pan over. Leave cake to cool in pan completely before unmoulding.
Recipe by Anncoo Journal at https://www.anncoojournal.com/yuja-chiffon-cake/