This is more hack your cookie than making the cookie from scratch. I am more a roasting and grillin' guy, ok, frying
so I really don't do dessert baking.
Grab a package of Oreos or similar double-sided cookie with creme stuffing in the middle. Would even work with Vanilla Wafers but then I would have to come up with another punny name.
You will need:
Instant coffee - whatever brand you like, there is espresso powder also
Non-dairy creamer powder - any flavor - not really necessary but can add bulk and flavor to the mix
Confectioners sugar ( castor sugar in the UK?) - this is the fine stuff mistaken for that other stuff, do not inhale
Shortening - lard-like substance made by various industrial edible oil cracking processes