Diffords guide book calls for 1.5 oz bourbon, I used rye…but then I see online a mixture. Used Bacardi 8 that was in my cabinet. Very full and flavor toward definitely a supper and I’d agree…softens as the single cube dilutes..
As per David Wondrich I used Rye Whiskey and served in a coupe. Wowza! Rye slightly softened by the rum but boosted with extra rummy flavours. Dark red fruit and spice with a liquorice finish. In a word…intense.
A perfect evening cocktail. Sipping while watching a Baroque streaming concert. This is definitely a cocktail which benefits from a very, very long stir and some time to breathe. The bourbon is very forward with the other flavours enhancing the secondary taste. Softens as the ice melts. Perfect to unwind after the day.