'- 100 gram (3.5 oz. / ~ 14 tablespoon) cake flour- 1 teaspoon baking powder- 1/8 teaspoon salt- 5 egg yolks- 30 gram (1 oz. / ~ 3.5 tablespoon) powdered sugar- 80 ml (1/3 cup) neutral flavored oil (e.g. vegetable, canola, e.t.c.)- 100 ml (6 tablespoon + 2 teaspoon) freshly squeezed orange juice- 1 teaspoon orange zest- 5 egg whites- 1/2 teaspoon cream of tartar (or 1 teaspoon vinegar)- 60 gram (2 oz. / ~ 7 tablespoon) powdered sugar

1. Preheat oven to 350 Fahrenheit (180 Celsius).2. Sift together cake flour, baking powder, and salt.3. In a mixing bowl, beat egg yolks and 30 gram powdered sugar until well mixed. Add in oil, orange juice, and orange zest. Beat until well mixed. Add the cake flour mixture in 3 batches, and beat until well mixed. Set aside.4. In another mixing bowl, whisk egg whites until foamy. Then add cream of tartar (or vinegar). Add powdered sugar in 3 batches, and keep whisking until stiff peak.5. With a spatula, gently fold the egg whites into the egg yolks batter in 3 batches.6. Pour into a 7-inch angel food pan (I use the one from Wilton). Gently tap to remove air bubbles. (*)7. Bake in preheated oven for 15 minutes.8. [Optional] Remove pan from oven, quickly make thin slits on the top to control the cracking pattern of the chiffon cake.9. Reduce heat to 320 Fahrenheit (160 Celsius). Continue baking for another 25-30 minutes, or until a cake tester comes out clean.10. Cool the cake by inverting the pan to prevent the cake from collapsing. Once the cake is completely cool, gently run a thin knife along the edges of the pan to unmold the cake.