Combine aged rum, falernum, and aromatic bitters in a mixing glass.
Add ice and stir for approximately 20 seconds until well chilled and diluted.
Strain into an old-fashioned glass filled with crushed ice.
Optionally, float dark rum over the back of a spoon onto the surface of the drink.
Garnish with a lime wedge.
The name 'Corn 'n' Oil' refers to the visual contrast between the golden falernum and the dark rum, which sit together like oil on water - a effect best preserved by gently floating the dark rum as a final layer rather than stirring it in.
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