For the mocha cookies, cream butter with sugar, then beat in egg.
Stir in flour and hazelnuts. Dissolve coffee in a little water and mix in. Use 2 teaspoons to place small heaps on the baking sheet and bake at 200° for 8-10min.
Let cool. Mix powdered sugar with coffee and water to make a glaze. Put a dab of icing on each cookie and decorate with a mocha bean.