The choice of using white vs brown sugar in blondies can affect their texture, flavour and appearance. Brown sugar contains molasses, which gives it a moist and chewy texture and a caramel-like flavour. When used in blondies, it can produce a softer and more tender texture, plus a richer, more complex flavour. Brown sugar can also give the blondies a darker colour due to the molasses content. White sugar, on the other hand, does not contain molasses and has a more neutral flavour. When used in blondies, it can produce a crisper and more delicate texture, with a lighter colour. Brown sugar should always be your first choice.