Earl Grey Chiffon Cake (伯爵雪芳(戚風)蛋糕)

Ingredients
2 tsp. (3 g) Earl Grey loose tea leaves
1 Tbsp. (5 g) Earl Grey loose tea leaves
6 Tbsp. (90 ml) hot water
3 large eggs
85 g (3 oz, or ½ cup and take away 1 Tbsp.) sugar, separated
3 Tbsp. (40 ml) vegetable oil
75 g (2.6 oz., or ⅔ cup) cake flour 
1 tsp. (3 g) baking powder

Equipment
1 17-cm (about 7”) chiffon cake pan (Do not grease the pan. Chiffon cakes cling to the sides to rise. If you grease the pan, they will not rise as high.)

Instructions
- Preheat the oven to 340F (170C).
- Put 1 Tbsp. Earl Grey loose tea leaves in a fine sieve over a bowl and pour 4 Tbsp. of hot water to seep a strong tea. After cooling down, drain and make sure you have 4 Tbsp. (60 ml) Earl Grey tea and set aside.
- Separate 3 eggs to whites and yolks.
- In a large bowl, whisk 3 egg yolks and roughly ⅓ of 85 g (3 oz) sugar.
- Add 3 Tbsp. vegetable oil, 4 Tbsp. tea, and whisk all together until combined.
- Add the 2 tsp. powdered Earl Grey tea in the egg mixture and mix well.
- Sift 75 g (2.6 oz) cake flour and 1 tsp. baking powder into the egg mixture in 3 increments. - Whisk until totally incorporated and make sure there are no lumps.
- Using a stand mixer (make sure there is no trace of water or oil), whip the egg whites on medium low sped (speed 4) till opaque, foamy and bubbly. Add ⅓ of the remaining sugar and continue whipping. After 30 seconds or so, increase the stand mixer speed to high (speed 10) and add the remaining sugar slowly in small increments. It takes about 2-3 minutes until stiff peaks form (from the moment you switched to speed 10, but this is just a rough guidance and it will vary based on stand mixers.). To check on stiff peaks, pull up your whisk and see if you can make strong “peak” that stays still without bending down.
- Using a spatula, fold in ⅓ of the egg whites in the batter until the mixture is homogeneous.
- Fold in the rest of egg whites in 2-3 increments and mix gently until the mixture is homogeneous.
- Pour the batter into the ungreased 17 cm (7”) chiffon cake pan in same location to prevent from foaming more bubbles. To remove or prevent air pockets before baking, run a skewer (chopstick, knife or spatula) through the batter and then drop gently a few times.
- Bake in the preheated oven for 30-35 minutes, or until a toothpick inserted comes out clean and the top of the cake springs back when gently pressed. If the top gets burn too quickly, cover the top loosely with aluminum foil.
- The cake must be cooled upside down in its pan so that it stretch down instead of collapsing. Stick the cake pan on a tall heavy bottle or invert the cake pan onto a cooling rack (if you use angel food cake pan). Let it cool completely. To extract the cake, run a thin sharp knife or thin offset spatula around both the outer and inner edge of the cake and then tap the cake out onto a serving plate.
- Dust powder sugar on top, if you like.

Notes

- All-purpose flour and cake flour do not perform the same. Cake flour is more delicate, and if you use all-purpose flour instead of cake flour, the texture will be dense and tough. 
- Do not overbeat or underbeat egg whites -- your cake may fall. Egg whites should be stiff but not dry.
- When you finish making meringue, make sure to fold in egg whites gently so the tiny bubbles don’t deflate.  If you deflate the egg whites too much, the cake will not be fluffy.

Reference
http://www.justonecookbook.com/earl-grey-chiffon-cake/