Can we sub granulated sugar for powdered? And can we reduce the amount of sugar or will it adversely affect the texture of the cookies?

Sugar substitutions are tricky. One can *not* make powdered sugar by grinding granulated sugar. If you're finding these cookies to be too sweet - I say take 10% out, but, yes, removing a portion of the sugar will change the texture of the cookie. Besides the obvious sweet factor, sugar adds moisture. I'll admit that I can't see the recipe or the method that you are referring to, but cookies like this tend to have eggs, and or egg yolks, and or egg whites, whipped with sugar and folded into melted chocolate. Confectioner's sugar sometimes creates a more stable meringue, thus affecting how much, or how little, the cookie spreads, so that might be affected, as well, with a substitution.

I am a big fan of not following recipes to see what will happen. None of us really *know* what will happen if you do or do not follow this recipe to a T, so I say - go for it - the worst that can happen is you have a very crunchy chocolate cookie, eh? Just Make sure if you omit any sugar to watch them carefully in the oven - a less moist/more brittle cookie will need less baking time. Do let us know how they turned out, and what you did, eh?

It's pretty easy to make powdered sugar. For every cup of sugar you add 1 tbs cornstarch and blend it until powdery. It didn't work very well in my Cuisinart, but it worked great in my blender.

Are you wanting to use granular sugar for the dough or to put on the cookies at the end? For the later, it would work. For the dough, I don't think I'd try it with granular sugar. I'm not sure exactly how they would turn out compared to the recipe. You can always put granular sugar in a food processor, blender or coffee grinder to make powdered sugar.