Why is it important to allow room for cookies to flatten and spread during baking?

Allowing room for cookies to flatten and spread during baking is essential for ensuring that drop cookies form correctly. When dough is placed on a baking sheet, it starts in a mound shape, and as the cookies bake, they will naturally spread out due to the melting of fats and the development of gases within the batter. If cookies are too close together, they may bake into one another instead of spreading properly, resulting in uneven shapes and potentially affecting the texture and overall appearance. This is particularly true for drop cookies, which rely on that spreading action to achieve their signature look and mouthfeel.

While enhancing flavor, achieving a crispy texture, and avoiding burning are all important factors in baking, they are not the primary reason for ensuring adequate space between cookies on the baking sheet. The proper formation of drop cookies, characterized by their shape and texture, depends on the ability to spread out during the baking process.