Instead of instant espress powder, could we use shots of espresso? thanks

Medalia D'oro is a very nice espresso powder to add. I have used it for years and I would recommend it. You can also use an espresso shot as a substitute for the rum.

Or you could sub the espresso shot for the rum. If you do add the espresso along with the rest of the ingredients (and the rum), it will make a looser batter, but as long as you don't add more than a tablespoon or two of espresso, I think you'll be ok. The cookies may spread more but that may also be a good thing! Jenny melted all the chocolate when she made hers and this extra moisture had a good effect on the cookies. Good luck!

Espresso shots will add liquid to the batter and likely throw off the texture. I would just leave it out.