Ask Nancy

The biggest factor in whether your cookie is crunchy or chewy is the recipe you use. When choosing a recipe, those made with shortening tend to be chewier than those made with butter – butter melts faster than solid shortening, causing the cookie to spread more and become crunchy. Even half butter/half shortening will melt more slowly than butter-only. Using cake flour instead of all-purpose will often make your cookie puffier (it contains more moisture than all-purpose!). Also, if you add an additional tablespoon or two of flour, the cookies will spread less and be chewier. Cookies made with baking powder also set faster, spreading less and making the cookie chewier. Finally, if you chill your cookie dough before baking, the cookies will spread less when baked, resulting in a chewier cookie.