Granulated Sugar and Cornstarch Blend (Best Option)
1 cup granulated sugar + 1 tablespoon cornstarch yields approximately 1 cup powdered sugarPowdered sugar is essentially granulated sugar ground to a fine powder with a small amount of cornstarch to prevent clumping. By blending granulated sugar with cornstarch, you recreate this fine texture and anti-caking property, which is crucial for smooth batter and even sweetness distribution in vanilla cake.
To ensure success, use a high-speed blender or food processor and blend until the mixture is very fine. Sift the mixture before adding to the batter to avoid any remaining granules. This method works best when the sugar is dry and the cornstarch is evenly mixed.
Compared to store-bought powdered sugar, this substitute produces a very similar texture and sweetness level, maintaining the cake's delicate crumb and vanilla flavor without noticeable differences.