Chill an old-fashioned glass by filling it with ice
Let glass sit while you prepare the rest of the drink
In a mixing beaker with ice add bourbon, syrup, and bitters
Stir for about 15 seconds
Discard the ice from the chilled glass
Rinse glass with the absinthe and discard
Pour the whiskey mixture from beaker into the absinthe-rinsed glass
Gently squeeze the lemon twist by pinching the edges on both sides (yellow peel facing towards drink) over the drink to release its essence and rub the garnish along the rim of the glass