I would say the ginger beer float is optional; I made this without and the drink was delicious.

Moderated to confirm to larger proportions of Imbibe recipe, which is probably more authoritative, and added lime wheel garnish.

Revisited after a couple years in an effort to finish off my bottle of Canton, and I still think this is an amazing drink. I do prefer it with a bit less lime however, and the last couple of times I made it I added a little orgeat since it plays so well with the Fernet Branca and the ginger. I amend my previous comments about the ginger beer being optional- it's a little syrupy without. However, the drink is on the sweet side and the ginger beer only adds to that. I've heard that King's ginger liqueur has more ginger flavor than the Canton that I finally finished, so I wonder if that with regular soda water would give enough ginger kick without getting too sweet.

Never having tried it with Canton, I just made this with King's Ginger, 3/4 oz of lime, and soda instead of ginger beer.  I thought the flavor balance was good, not too sweet, but the ginger was more subtle than big-kick.

Curated to add instructions for make the Sweet Corn Simple Syrup.

Can someone explain where the second portion of lime juice is to be used, please?

That's a good question. The link is broken, and the current cocktail menu doesn't have this on it. Perhaps the OP can chime in, but it's not lime peel as garnish. Thanks,  Zachary

That must be what the secret is.

It's a good drink, no doubt. I particularly enjoyed how it highlighted the bitters. My main critique is I felt the liquors got buried, and considering the investment of infusing the bourbon with peach, I question how worthwhile it is. Probably worth a try if you have peaches you want to get rid of, but it's more of a special occasion drink than a regular rotation cocktail.

I pulled into Nazareth and *really* enjoyed this drink.

Used Akashi, Meletti instead of Campari, and grapefruit instead of lemon bitters. The liqueurs support the whisky beautifully. 

Curated this slightly - corrected the bitters to 1 dash which I'd imagine is correct. Thanks,  Zachary

Quick question - is the amount of bitters an ounce or a dash?

Must be a dash.

I get the smoke, obviously, but from whence the Butter and Lemon? Sounds interesting. Also sounds like the sort of thing I might prefer neat. If you like this, you might try the Bernet Frankenstein, a mixture of Islay Scotch, Punt e Mes, and Fernet Branca, served neat.

One question: is the garnish a lemon wedge, slice, or what. It's a bit hard to tell in the picture. It also looks like the coupe is rimmed with something, but it might just be the light hitting it oddly.

Used Sheep Dip Islay in place of Peat Monster. 5 star.