Fill a rocks glass to the top with ice cubes
Pour in 0.5 oz of absinthe and 0.35 oz of still water, then set aside
Place a sugar cube into a mixing glass
Soak the sugar with 3 dashes of Angostura bitters and 3 dashes of Peychaud's bitters and muddle
Add 1.5 oz of cognac and 1 oz of bourbon
Fill the glass with ice cubes and stir until the sugar dissolves
Pour out still water, absinthe and ice from the rocks glass
Strain the cocktail into the aromatized glass
Garnish with lemon zest