The rum provides smoothness and the bitters add a nice bite to this hybrid version of the old fashioned.
1 ounce bourbon
1 ounce aged rum
1/4 ounce simple syrup
1/4 teaspoon walnut bitters
1/4 teaspoon orange bitters
1/4 teaspoon Angostura bitters
orange peel twist or walnut half for garnish
Place sugar and bitters in a mixing glass with a little water. Stir thoroughly and strain into an old fashioned glass over ice. Top with an orange peel twist.