Q: Can I substitute brown sugar for white sugar in zucchini bread?
A: Yes, brown sugar (light or dark) can be substituted cup for cup with granulated white sugar when baking, including when making zucchini bread.
It might, however, make the color of the bread a little darker.
When swapping brown sugar for granulated white sugar, keep in mind that brown sugar imparts a slight molasses flavor to baked goods and also tends to produce a chewier texture.
Such changes might be desirable for chocolate chip cookies but not for a more delicate pastry.
