Line cookie sheet with parchment paper; set the cookie sheet aside.
In a small bowl stir together water and coffee crystals or espresso coffee powder until dissolved; set aside.
In a large mixing bowl beat butter with an electric mixer on medium to high speed for 30 seconds. Add sugar and salt. Beat until combined, scraping sides of bowl occasionally. Add eggs and coffee mixture; beat until combined. Beat in as much of the flour as you can with the mixer. Using a wooden spoon, stir in any remaining flour.
Drop dough by slightly rounded teaspoon 2 inches apart onto the prepared cookie sheet; spread dough into 2-inch circles.
Bake in a 350 degree F oven for 9 to 11 minutes or until browned around the edges. Cool on cookie sheet set on a wire rack for 2 minutes. Transfer cookies to a wire rack; cool.
When cookies are cool, fill a pastry bag fitted with a very small round tip with Coffee Icing. Pipe icing onto cookies in a zigzag pattern. Or, thin icing with additional whipping cream to make icing of drizzling consistency; use fork tines to drizzle icing over cookies. If desired, sprinkle with crushed coffee crystals. Makes about 20 cookies.
Stir together instant coffee crystals or dash of espresso coffee powder and 1 tablespoon of the whipping cream until coffee is dissolved. In a small mixing bowl stir together powdered sugar, the coffee-cream mixture and enough additional whipping cream (1 to 2 tablespoons) to make icing of piping consistency.