Very good!! Didn't have the dram so just soaked ground allspice & nutmeg in the bourbon (use coffee filter) for 5 min. Simplify it and just use 1/4 oz maple syrup instead of mixing up a solution with water. Used regular lemon juice, but curious to try with Meyer. Also, added half an egg white to give it a little foam.

Been a cocktail fan for 25 years. This is one of my favorites. The only mod I make is using regular instead of meyer lemon juice (availability).

A bit sweet. Better as 3-2-1.5.

I find Meletti has the gestalt of chocolate in it. This sounds very nice. Adding it to my suggested cocktails now...

Regarding the prior comments:  Choose your rye carefully; WhistlePig 10 years and Templeton 4 years are light in flavor and sweet. Templeton 6 years, Wild Turkey and Knob Creek, however, have more body and different flavors. The rye you choose will have a defining impact on the taste of this drink.

Choose carefully, also, your vermouth. Antica Formula is my favorite vermouth. I used, however, Vermut Negre, a dark but not too sweet vermouth. I then used only two drops of Xocolatl Mole, not three, which was fine for me. This was the first time I drank this cocktail, but I humbly rank the resultant cocktail at 4.5. I hope my suggestions are helpful.  

Bullitt rye and Bitter Mile Chocolate Chili bitters. It left a zing on the lip. A nice Manhattan changeup.

So.... I think I like this best with 2 tablespoons of batter, 1 oz Smith&Cross, and filling the 8 ounce glass with hot milk. 2 ounces of alcohol per 8 ounce glass is overkill.

Curated to add attribution and rewrite instructions in our own words (and more concisely).

I'm making this now, using Carpano Antica Forumla because, sadly no Dubonnet Rouge on hand. Very nice. I'm very fond of the word "crux." As a retired rock climber, the crux of a climb is its single most difficult move. Once you're past the crux, you know that you can make it. Fond memories.

Delicious cocktail. Great sidecar alternative, particularly if looking for something less cognac forward. 

I made this today, using Pierre Ferrand 1840 cognac, Dubbonet, and Pierre Ferrand dry Curacao. I poured a little heavy with the cognac, but didn't need to. The end result was on the dry side, very bright, with underlaying complexity from the aromatics in the Dubbonet. Delicious. I will definitely make again! ****

Do 1/2 of the Elderflower

I agree with other comments in that it isn't quite there. Good but not great.

The John Gertsen riff, the Means of Preservation, at Drink in Boston is a bit better:

https://kindredcocktails.com/cocktail/means-preservation

Odd that Ransom's is listed here, and the recipe is off as well. I don't have the PDT Cocktail book (2011) but the 2009 links to this drink both use Hayman's Old Tom. These gins are very different in flavor. I tried this cocktail tonight based on http://www.cocktailchronicles.com/2009/05/04/3030-18-the-ephemeral-than… and http://looka.gumbopages.com//archive/2009-05.html#1. Both used Hayman's Old Tom (1.5), Dolin Blanc (1), 2 tsp St. Germain (1/3 oz), and 3 dashes of Celery Bitters.

Hayman's Old Tom hit our market in 2008 and Ransom's OTG was a few years later around 2011. So historically, it makes sense why the earliest ones would have Hayman's (also, the distillery already had their vintage recipe for OTG ready to go and didn't need to develop one so when Eric Seed of Haus Alpenz approached them, they got right on it).

The Ephemeral was originally made with the Ransom. Back in 2009, both Ransom and Hayman's Old Tom gins were available in Oregon, but I don't know how far Ransom had got with their non-local distribution. Shenaut's blog is still up, if you want to see his publishing of this recipe.

http://rousingthespirit.blogspot.com/2009/08/ephemeral.html

Thank you for providing the original inception/recipe. Ransom it was, I'll have to give it a spin. Interesting how the volumes have gone up over the past decade in so many recipes, from ~2.5 to 3+, or here from 2.4+ to nearly 3.2. oz. (I suppose this is as much for fill level in glassware as anything else.) This can get tricky when trying to keep the ratios of the smaller components the same.

It is fortunate that the celery bitters are listed in drops in the original, much more useful than dashes. Dashes can be anywhere from 6 to 10 drops depending on who is defining it. (And with Fee Brothers, trying to get anything out of the bottle with a simple dash can be problematic, which is why I only use dropper for their bitters.) I was using 8 drops/dash for years, but the measurements I have made suggest 10 makes more sense. Increasing drink volume by 1/3 (as per the current recipe) puts the drink closer to what some would call 2 dashes. The elderflower liqueur becomes a "generous barspoon."