When baking homemade cookie recipes, it’s best to use two baking sheets so that you don’t put cookie dough down on a hot pan. If cookie dough is put onto a hot cooking sheet, it will change the structure of the cookie, causing them to spread too thin. Using two cookie sheets allows one to cool before adding cookie dough. If you don’t have two baking sheets, you can simply allow the pan to cool before adding another batch of cookie dough to it.