We discovered the use of rum in place of cognac in a Vieux Carré thanks to a comment by Collin Westgate on our Vieux Carré page saying that he'd discovered...
Blasphemous I know, but I think I like this better than the Vieux Carré. It's both softer and warmer. I used Vya vermouth, which also really amped up the Christmas spice character. Lovely