Sugar cookies are made by using a delicate formula that at first doesn't seem scientific. All of the ingredients serve a purpose, and when you replace one ingredient or use a slight variation, the resulting cookies will be affected. For example, switching from brown sugar to white or granulated sugar can change the way your cookies turn out. That's because white sugar is a large part of the recipe, about 30-40% of the ingredients. Sugar also affects the way the cookies rise and spread. In many go-to cookie recipes, it makes a dough that puffs up a little yet keeps its shape after baking.

When you substitute brown sugar for the granulated form, the cookie is puffier, chewier, and thicker than many bakers prefer. The puffy surface is harder to decorate, and the shape can also spread to slightly distort the molded or shaped dough. However, the molasses in brown sugar adds a rich flavor. It's best only to replace half of the granulated with its brown counterpart. The result is a thick cookie with crispy edges that keeps its shape and has a flat surface that's easy to decorate. No brown sugar on hand? Not a problem: You can substitute it with white sugar with added molasses.