Add the dark rum, maple syrup and Angostura bitters into a mixing glass with ice and stir until well-chilled.
2.
Strain into a chilled cocktail glass.
3.
Garnish with an orange twist.
Notes
Not all maple syrups are created equal, so start with less and add more as needed (it’s easy to over-sweeten the drink, but harder to add rum to go the other way).