Fill your stirring glass halfway with ice cubes.
Add a few drops of Angostura Bitters.
Next, a few drops of orange bitters, which can be replaced with orange peel instead.
Pour in sugar syrup. If you're using brown sugar, stir for a few more minutes to make sure it dissolves.
Slice/peel a piece of an untreated orange and squeeze it over the glass and then add it in.
Add bourbon and then fill the rest of the glass with ice cubes.
Fill a cocktail/whiskey glass with ice cubes.
Stir your cocktail for about 30 seconds to ensure everything is well distributed.
Remove the ice cubes from your cocktail glass and add new ones.
Strain the liquid into your cocktail glass.
Slice a new piece of orange peel and run it around the edges of your cocktail.
Cheers.