Typically, you make them with very little sugar in the dough; they're sweetened instead by rolling them through a mountain of powdered sugar after baking. (biggirlssmallkitchen.com)
Your two best choices are fruits with little sugar content. (exercisegoals.com)
I don't really consider it a treat because I only eat SUPER dark (like 72 % +) chocolate with very little sugar in it. (mamanatural.com)