Measure the vodka, Cointreau, orange juice and orange-flower water into a cocktail shaker.
Add the orange zest and ice cubes.
Divide into two old fashioned glasses and strain over ice.
Add club soda to top up the glasses and serve.
* If you don’t have orange vodka, you can simply soak the zest of 1 orange in about 1 cup of vodka for a couple of hours, or overnight if you can. * You can find orange-flower water in Middle Eastern and other gourmet specialty shops.