Stir all ingredients with ice until chilled. Serve in a martini glass.
My homemade rhubarb vodka has the full flavor of the rhubarb, including its bitterness. If the drink seems too light on the palate, add a dash of rhubarb bitters. The drink should be just sweet enough be smooth at first sip, but the bite of the rhubarb should be there in the end.