This is an easy way to turn your boring New Year's Eve toast into something more tasty, if you're working with cheap champagne. Just add a sugar cube baptized with 2 dashes of the bitters of your choice.
These were a big hit at the Old Colony Club's Casablanca-themed party in 2018.
A related cocktail is the French 75, also hugely popular. This, of course, begs the question "Will I get in trouble if I add a little gin to my Champagne Cocktail?" - I won't tell anyone if you do!