You have discovered some of the alchemy of cookie textures - at least as they affect your particular recipe. When you know the alchemy, it helps you to pick the type of cookie you want from the ingredients list in the recipe to begin with, as well as the ratio of ingredients, or the knowledge helps you to alter a cookie recipe to get the results you want.

Cookies are formulated a lot like cake, except there is less liquid. You can alter a recipe intentionally or unintentionally. Just adding or decreasing the amount of flour by a tablespoon or two will get different results.

Leavening agents in cookies contribute to the flavor, texture, spread, and color. Baking powder helps to produce a lighter-colored and puffier cookie. Baking soda makes a cookie spread and brown more.

You can substitute a small portion of the flour with rice flour to make cookies crispy. Make your own rice flour by milling short- or medium-grain rice in a coffee/spice mill. Long-grain rice doesn't work as well for baked goods. The amount of gluten in the flour you use can also alter the texture. If you accidently use bread flour instead of all-purpose, you'll find a tougher cookie as a result. Gluten absorbs a lot of moisture - alter the amount of gluten in the flour, and keep the same hydration, and you'll get a different texture.

Butter VS Shortening - Butter contributes to a crisp cookie (think shortbread cookies). Shortening typically contributes to a cakelike and softer cookie, but they are also crumbly and more dry (which seems to be a contridiction of characteristics - much like getting puffy, chewy cookies which are opposite attributes when talking about cookies).

If your cookies soften after they are in storage, it's probably moisture migrating from the crumb of the cookie to the surface of the cookie. There is more moisture in butter than shortening, but by under-baking cookies, some of that moisture remains in the crumb which migrates to the outside. Other ingredients in the cookies can also absorb and hold moisture, which migrates to the surface.

There are a million and one things that contribute to the finished product when you talk about attributes of a cookie. Everything from sloppy measuring to the type of pan you baked your cookies on, and everything inbetween contributes something. And just when you think you have it all figured out, you bake your T & T recipe on on a humid day, or use new bakeware, or have the rack in the oven in a different place, or didn't allow the dough to rest a few minutes before forming the dough balls, or your kitchen was hot and the fat in the dough melts before you get the dough onto the baking sheet, or your butter was too soft when you mixed your ingredients, or, or, or.....and all the sudden you have a new end result to your T & T cookie recipe - asking "WHAT HAPPENED"?

I think I'm having flashbacks to judging cookies at too many fairs (LOL)!

-Grainlady