Rinse the Pickled Sakura (8) to remove excess salt and soak for 45-60 minutes. Gently pat dry the flowers on paper towels. Line the flowers on the base of a 17-centimeter tube pan, set aside.
Separate Egg (4) Yolks and Whites. You will need 3 egg yolk and 4 egg whites. Set aside.
In a large bowl, mix 3 Egg Yolks, Granulated Sugar (25 gram) and Corn Oil (40 gram) together, mix well with a hand whisk. Add Natural Unflavored Yogurt (100 gram) and Honey (1 teaspoon) into it, mix well till combined and smooth.
Sift in All-Purpose Flour (60 gram), Rice Flour (20 gram) and Sakura Leaf Powder (2 teaspoon) and mix well again.
In a mixing bowl, whisk all the Egg Whites and Cream of Tartar (1/4 teaspoon) till frothy, gradually add in Granulated Sugar (50 gram). Continue whisk egg whites till stiff peak forms.
Fold ⅓ of egg whites into the yolk mixture. Then pour in the rest of the egg whites and fold gently until combined with a rubber spatula.
Pour batter into the prepared tube pan. Gently bang the pan on the table top to release air bubbles.
Place cake pan in the preheated oven 170 degrees C (340 degrees F) and bake for about 35-40 minutes.
When the cake is done, remove from oven and turn the pan over. Remove the cake from pan after cooling. Serve and enjoy!