Caster Sugar (Best Option)
1:1 by volumeCaster sugar is essentially finely ground granulated sugar, which allows it to dissolve quickly and evenly in the mascarpone and egg mixture. This rapid dissolution is critical in tiramisu to avoid any gritty texture and to maintain the creamy consistency.
When using caster sugar, ensure it is well incorporated by gentle folding to maintain the airy texture of the mascarpone mixture. It behaves identically to granulated sugar in terms of sweetness and moisture balance.
The final tiramisu will have the same sweetness level and mouthfeel as with granulated sugar, preserving the classic texture and flavor profile.