Cake Flour (1 ¼ cups): You must use cake flour, not all-purpose. Its low protein content prevents tough gluten from forming, ensuring the crumb remains exceptionally tender and soft.High-Quality Matcha Powder (2 tablespoons): The star ingredient. Use a premium culinary grade or ceremonial grade matcha. It should be vibrantly bright green. Dull, yellowish matcha will yield a muddy-colored cake with a bitter, fishy aftertaste.Granulated Sugar (1 cup, divided): Used to sweeten the batter and, crucially, to stabilize the egg whites. You will use ½ cup in the egg yolk batter and ½ cup in the meringue.Large Eggs (6 whole, separated): You need 6 egg yolks and 6 egg whites. They must be separated carefully (no yolk in the whites!) and should be at room temperature for maximum volume.Neutral Vegetable Oil or Canola Oil (½ cup): Unlike butter, oil remains liquid at room temperature. This is the scientific secret to a chiffon cake that stays incredibly moist and soft, even when chilled.Whole Milk or Water (½ cup): Adds necessary hydration to the thick egg yolk batter. Milk adds a touch of richness, while water allows the pure tea flavor to shine brighter.Baking Powder (1 ½ teaspoons): Provides a small amount of chemical lift to assist the whipped egg whites.Cream of Tartar (½ teaspoon): An acidic powder that stabilizes the egg whites, helping them whip to stiff peaks quickly and preventing them from deflating while folding.Fine Sea Salt (½ teaspoon): A critical flavor enhancer that cuts through the sweetness and balances the mild grassy notes of the tea.Pure Vanilla Extract (1 teaspoon): Adds sweet, floral aromatic notes that beautifully round out the earthy matcha profile.