Granulated Sugar and Cornstarch Blend (Best Option)
1 cup granulated sugar + 1 tablespoon cornstarch = 1 cup powdered sugarPowdered sugar is essentially granulated sugar ground finely with cornstarch to prevent clumping. This blend replicates the smooth sweetness and anti-caking property, crucial for even sweetness distribution in bread pudding custard.
To ensure the blend works well, pulse the granulated sugar and cornstarch until very fine, almost like flour. This prevents graininess and ensures the sugar dissolves completely during baking.
Using this substitute maintains the traditional texture and sweetness of bread pudding, avoiding graininess or moisture issues that other substitutes might cause.