The Borgers is an old drink, sourced from the pages of Pioneers of Mixing at Elite Bars: 1903-1933 and reworked by Frederic Yarm over at Cocktail Virgin. It’s essentially a Manhattan riff featuring Crème de Noyaux, which offers a nutty, herbal essence.
You could substitute a plainer almond liqueur like amaretto; it’ll be a little sweeter and less complex, but still quite pleasant. We’d stick with rye here, instead of bourbon or blended whiskey; the added sweetness from the noyaux works best with the peppery spice of rye whiskey.
The original recipe called for Angostura bitters; we also think it’s lovely with cherry bitters, to accentuate the almond notes.