Added some chocolate bitters and it was amazing. 

I tried this with Clement Rhum Agricole and Hardy Pineau des Charentes. It was good enough, but didn't wow me. I also tried cognac in place of the rhum agricole, and that was promising, a sidecar of sorts. Worth revisiting and tinkering a bit.

Drunklab recommended a very nice riff:

1 1/2 oz Bonal Gentiane Quina
3/4 oz Jamaican rum (Smith & Cross)
3/4 oz Rhum agricole
1/4 oz Lemon juice
1 d Bittermens Xocalatl Mole bitters
1 twist lemon

Very, very nice.

<a href="http://forums.egullet.org/topic/138481-bonal-gentiane-quina/?p=1969665"… reference</a>

That sounds delicious, but as much as I love Bonal, the Pineau is what makes this drink special, so it's really something else entirely and deserving of its own name .

Bonal has a Pineau-like base of lightly fermented grape must fortified with brandy, and some flavor notes in common with Pineau, but it's much more assertive, so my riff tastes quite different. I'm open to suggestions for a name.

I made this with Hardy Pineau and with Dusquene Rhum Agricole Blanc (100 proof). Will try it next with an aged Agricole but this balanced out perfectly for me.  Lean and even a little dry, I would say my result here with the Blanc is good enough that I would suggest others try it -- especially anyone who finds the original too sweet. 

This is a really delicious fall drink, with sweet, bitter, spice, and tart flavors all mingling happily. My bartender made this for me, and he used either a red or rose Pineau des Charentes, though I'd think white would work as well. I'll clarify next time I go in. I'm not a beer drinker, so I'm not sure how essential the Ephemere is, but the apple flavors do complement the brandy nicely.

Ephemere is a white ale brewed with apples and spices, so I'd imagine it's important to the ultimate flavor profile of the drink. Substitutes might be really good apple cider (from Normandy, if possible).

First try. I think the drink is nice, but a little one-note. I think fresh expressed orange peel would be better than Ango Orange. The Campari and Sloe Gin go together nicely, but merge a bit more than I would like. I wonder if Amaro CioCiaro / Amer Picon / Amer Boudreau might have a role?

Hmm.... fun indeed. If you're aiming to keep the Campari-Sloe Gin accord, change out the Rye for Anejo Tequila. I think you want more woody, less spicy to help separate the two. And the question is whose Sloe Gin are you using here?

Thanks, Zach

I'm using Plymouth Sloe Gin. OK, someone try Tequila next. A blanco with peppery backbone, or something that's seen wood?

This looks delicious- can't resist playing along, so humor my novice musings please :)

I made a variation using Don Julio anejo and the orange peel instead of the Angostura bitters. It was quite good, maybe a tad bit astringent (and I do like tart flavors). I was intrigued by the CioCiaro suggestion as well, so I tried using rye, subbing half the Campari for CioCiaro. That didn't work as well- the CioCiaro dominated, delicious as it is. I could see going back to tequila and adding just a touch of CioCiaro.

My Sloe gin is from the Bitter Truth; I'm not sure how it differs from Plymouth.

I think this a great concept for a cocktail. And the missteps still taste pretty good. I wonder if Cachaca would work here?

I gried eGullet's Dan Perrigan's New Red House (1:1:1:1/2 rye, Campari, CioCiaro, Lemon). Nice, but I prefer the tartness of the original 1:1:1:1 formula. I can see that those who like a touch of sweetness would like this. My recollection is that when I did this with Gran Classico for the Campari, it was magical. Alas, my bottle is gone so I'll have to try it again when I restock.

I then tried 1:1:1:1 rye, sloe gin, Ramazzotti, lemon. Meh. Ok, but not as good as the same drink with Campari instead of sloe gin.

Then I couldn't resist going back to the Last Word: 1:1:1:1 Tanqueray, sloe gin, Campari, lemon. (Ok, in truth some lime since I ran out of lemons). Enjoyable, but not as good as either the Last Word or the Paper Airplane.

Right now, my go-to drink of this sort is still the 1:1:1:1 rye, Campari, Ramazzotti, and lemon. I prefer it to both the Paper Plane (Nonino/Aperol) and Paper Airplane (Nonino/Campari). I think it is some sort of magical, synergistic combination. I also love it with Gran Classico and CioCiaro.

I have not had The Bitter Truth Sloe Gin, but I've read that it is more bitter than Plymouth. There is a recipe which calls for adding a touch of Campari to Plymouth to simulate The Bitter Truth.

Maybe tequila will be my next try unless a better idea is suggested.

That's interesting about the Campari. I have the Bitter Truth Sloe Gin (I brought back a bottle from New York) and I find it to be less punchy than the Plymouth, both in sweetness and tartness - it's more floral and complex, but mild. This makes it great in drinks that have an ounce or two of sloe gin, but modern drinks where the sloe gin is used as an accent (like the Transatlantic Giant from Beta) tend to see the other ingredients overpower the sloe, since these drinks are almost always formulated with Plymouth.

It's kind of like the Cocchi/Lillet conundrum: the former is the better product and works great in vintage recipes, but almost everyone uses the latter in modern drinks, so the balance is frequently off when you use Cocchi.

I followed Zach's suggestion, although I used a reposado (my error). Excellent. A nice step in the right direction. Recipe updated from rye to tequila. I dropped the grapefruit and orange bitters as unnecessary. Switched to lime from lemon juice.

Curated to show the origin of this riff.

Disappointing. I tried this with three different amari to see whether that could improve it, but I found it pretty insipid.