Add slices of blood oranges and simple syrup to drink shaker and muddle lightly.
Fill shaker 1/2 full of ice and add blood orange juice and bourbon.
Shake vigorously for 30 seconds.
Pour cocktail into 2 glasses filled 3/4 with ice. Top each with club soda and extra slice of blood orange for garnish.
Notes
* simple syrup can be made by heating equal parts water and sugar over medium heat until sugar is dissolved. Let cool completely before using in the cocktail.** Blood orange juice can be use fresh by squeezing your own blood oranges or purchasing pre-made.