Does caster sugar help make sponge cakes fluffier?

Yes, caster sugar helps make sponge cakes fluffier because its fine crystals dissolve more quickly than granulated sugar, which helps create a smoother and more细腻的蛋糕糊. Additionally, the higher surface area of caster sugar allows it to interact more effectively with the other ingredients in the cake batter, resulting in a lighter and airier texture.