Let butter come to room temp. Preheat oven to 350. Cream the butter and the espresso powder then let stand for about 15 minutes so the espresso dissolves a bit. Mix in the rest of the ingredients and refrigerate for at least one hour. Drop small mounds onto cooled baking sheet or use 1 inch scoop. These are bite sized cookies. Bake for 10-11 minutes until just slightly browned. Cool completely then frost. Sprinkle lightly with cinnamon.
For the frosting mix everything together except the cinnamon and add just enough milk to get to a spreadable frosting.