This 2016 recipe list has a less adapted recipe: https://read.dmtmag.com/i/633762-cheers-january-2016/27?

Calls for Cutty Sark Prohibition, Single Malt Scotch (not Speyside -- my guess is Islay), and 1/4 oz black pepper tincture. And attributed to Matt Piacentini.

Difford's altering of recipes strikes again. Unfortunately, the Cheers mag link is now giving the message: "The owner of this Flipbook is disabled". I think I was able to see your link when you originally posted it several weeks ago, and it confirmed what you said about the recipe. Additionally I found a 2015 description confirming much of this in https://www.nytimes.com/2015/08/12/dining/cocktails-on-the-fringe.html (I used the Wayback Machine to get around the paywall.) Another 2016 link https://www.boxesandbooze.com/cocktails/passing-cars provides the peppercorn tincture recipe. An Islay single malt makes the most sense to me considering the cocktail name has peat in it, although this final link says Talisker 10yr. For the blend I have been using the Cutty Sark Prohibition frequently after "discovering" it in your books & site for other cocktails. I will curate the cocktail to list the creator, update the year, and correct the Scotches involved to the original, plus provide the tincture info. I am also changing the reference link to your site since Difford's made some alterations.

Anyone have directions for preparing the popcorn-infused vermouth?

The instagram for the cocktail says "Vermouth infused with Pop Corn (Sous-Vide at room temperature for 24 hours)".

I've not had this drink, so am just guessing at a starting point... Put a handful of popcorn and 50 g of clarified butter per 250 mL of vermouth, vacuum-sealed (using either a chamber sealer and bag or the jar sealing attachment of a cheaper vacuum unit), left for a day, & double-strained. Possibly add salt.

I'm impatient, so would probably try rapid infusion via iSi instead & tweak ratios to personal taste (or taste memory for those who have had the drink).

I like the ingredients separately, but this drink just did not come together for me.

Needs some dilution and time to open up.

This one will depend a lot on the specific components used if one considers the reference recipe & substitutions there. Zucca is quite sweet with a rich umami/smokiness to it, while Sfumato is much less sweet/and more intensely bitter. (For some cocktails I prefer a 50:50 mix of the two to create the right balance.) Lillet Blanc is a light touch, neither sweet nor bitter, while Cocchi Americano is intense, much sweeter but also has far more cinnamon spice and quinine bitterness. So there is some room to dial the cocktail in to one's tastes. It wasn't clear to me which rum was originally called for, I didn't think the Flor de Cana 4 yr extra dry would have enough flavor, but I didn't have the 4 yr Anejo Gold on hand. I hedged for something between with Bacardi Gold. Overall the recipe worked (Bacardi Gold/Lillet/Zucca) trending semi-sweet with rhubarb bitterness and smoky/umami, but I will retry with the Anejo Oro.