I can not recall the first time I heard about amaranth, but it was sometime pretty recently - the last couple of years for sure. It is an "ancient grain" - recently experiencing a renaissance because of its super-health properties. When I saw it in the bulk foods section of the grocery, I scooped out a baggie full of the teensy cous cous shaped pellets, and figured I'd decide what to do with them later. I assumed they could be cooked like rice or bulgur or quinoa, but when I finally got around to searching for recipes, I mostly found options for amaranth flour.
These cookies use a mix of amaranth and wheat flour, but then call for rolling the dough in the grain before baking, sort of like rolling in chopped nuts or powdered sugar. I decided I could get pretty close to making my own flour by pulsing the grain in a coffee grinder, and it was still a little rough - sort of like corn meal (similar to another of my favorite butter cookie recipes!), but it worked really well.
Ultimately, I opted to make a couple of changes, but I was thrilled to get the majority of inspiration from Maria Speck's recipe. I decided not to roll the cookies in more of the grain, and felt that the intended flavor and texture came through nicely just by using the home-ground "flour." I also didn't have walnuts, so I substituted pecans, and topped with a dollop of boysenberry jam rather than a whole nut.