The ingredients you use and how you shape your cookies both play an important role in whether your cookies turn out crispy or chewy. The type of flour and sugar you use, if your cookie dough contains eggs, and whether you use melted or softened butter all factor into the crispy-chewy equation, too.
To explore one side of the crispy-chewy conundrum, we created an edible science experiment for kids in The Complete Cookbook for Young Scientists (you can also find it on our kid-friendly website). Kids bake one batch of cookies with white granulated sugar, and one batch of cookies with dark brown sugar. Naturally, there’s a taste test to help them determine the results.