Don't know who rl is....but I always leave any leavening out of shaped or cut out cookies. It makes them rise and get puffy and lose their shape.
If you like a "cakey" cookie, leavening will help...if you like your cookies thin and crisp, leave it out.
Linda C

Thanks Linda. I tend to like cookies without leavening. Glad to hear I can leave it out most of the time. When you leave it out do, you increase the salt?

I'm not rl, but I'll take a stab at the alchemy of cookies.

It all depends on the ingredients and the type of cookie you are trying to make.

Both baking soda and baking powder react chemically to make millions of tiny bubbles of carbon dioxide.

Baking powder reacts twice, once when you add the liquid ingredients, and again in the oven from the heat. Both help to lighten the cookie texture. Combined with other ingredients that create a honeycomb-like texture, will give you a cake-like or soft cookie. If you use cake-making type mixing (cream the fat, etc.) it will help contribute to a more cake-like cookie.

If you are going to make large batches of dough and/or store dough in the refrigerator or freezer, choose recipes that contain baking powder so that you get that second reaction from the leavening in the oven. Soda just doesn't have the endurance. Baking powder gives you light-colored and puffier cookies.

Soda is an alkali and it reacts with an acid ingredient (such as citrus juice, vinegar, apples, berries, honey, yogurt, sour cream, buttermilk, bananas, carrots, pumpkin, molasses, cocoa/chocolate, etc.). Without the acid ingredient, soda can't leaven properly. Without the acid ingredient, carbon dioxide is still produced, just not as much. The unneutralized soda will give the baked good a "soapy" taste. It can also turn the pigment in flour kinda' yellow, as well as the colors of molasses and chocolate. Baking soda makes a cookie spread and brown more.

Cream of tartar (an acid) is another leavening agent used in cookies, often coupled with baking soda. You can make homemade baking powder by mixing one part baking soda with two parts cream of tartar. If using this you must mix quickly and get the item/s in the oven quickly or you will be left with hocky pucks. This leavening works very quickly.

Other leavening agents include steam (from liquid ingredients) and separated and beaten eggs also leaven different types of cookies. So you don't always require a chemical leavener for cookies.

-Grainlady

Kathy, I am one of those people that follows recipes as they are written.......at least the first time. I think Grainlady probably covered the subject as well as I have seen anyone do and I would go with what she says. Some cookies I want soft and cake like, others I want crisp so I add the baking powder, soda, or cream of tartar as the recipe indicates.
Happy Cookie baking.
RL`

Thanks Grainlady. The "ins and outs" of leavening is interesting. I will hear you "talking" as I measure the B soda and B powder from now on. You must be more than an everyday baker!
RL, I have many of your TT cookie recipes copied and pasted. I'm anxious to make the Honey Almond Delight. Thank you
Kathy

Kathy, hope you enjoy all of the cookies......the Honey Almond Delight was given to me by a very special lady and very good baker. Let me know how you like it.
RL`