What makes cookies chewy vs cakey is the amount of sugar used and the amount of baking powder or soda or the amount of eggs used.
A higher sugar to flour ratio leads to more moisture and chewy cookies and using the proper amount of baking powder or baking soda and using the proper amount of eggs.
Cakey cookies are often a result of too much baking powder or too much baking soda or too many eggs which result in a fluffy and cake like texture to the cookies.
The secret to chewy cookies is to use an extra egg yolk and cornstarch and more brown sugar than white sugar.
Using more brown sugar than white sugar when making cookies results in a softer, chewy and moisture cookie.
Using an extra egg yolk increases the chewiness of the cookies.
Also rolling the cookie dough balls to be tall and lumpy instead of wide and smooth will give your cookies the bakery style textured thickness.
To make cookies chewy without cornstarch.
Go heavy on brown sugar. It has more moisture than its granulated counterpart, which means the cookie comes out less crispy.
Choose margarine or shortening instead of butter.
Use baking powder instead of baking soda.
Rest your dough.
Shorten baking time.
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.
Cookies that are dense and chewy incorporate more moisture into the batter.
This can be achieved by making substitutions with wet and dry ingredients, or even just changing the way you incorporate certain ingredients.