Preheat an oven to 350 degrees F.
In a medium size mixing bowl cream the butter and sugar with an electric mixer until it is a light yellow color, about 2 minutes. Combine the flour, baking powder, salt, cinnamon and lemon zest and add to the butter mixture. Add the water and mix with a hand mixer, set on low speed, until the water is fully incorporated into the mixture. Do not over mix. Form the dough into a ball with your hands. Wrap it is plastic wrap and refrigerate it for 30 minutes. Turn the dough onto a lightly floured board and roll it into an 8x10 x ¼ inch rectangle. With a sharp knife cut 18 (3 inch) diamonds out of the dough. Grease a cookie sheet and place the cookies on the sheet. Brush the tops liberally with the melted butter. Bake just until the cookies start to color, about 15-18 minutes. While the cookies are baking combine the glaze ingredients. Remove the cookies from the oven and allow them to cool for about 3 minutes. While they are still warm spoon some glaze onto the center of each cookie and then spread it almost to the edge. Allow the cookie to stand undisturbed for about an hour. Serve with espresso if desired.