seriously yummy!

Significantly revised to be less orange, more ginger-forward, spicier, and less sweet.

I like this quite a bit.  It's like a spicier, orangey-er daiquiri. I almost want to throw a little club soda on top of it, cause I'm crude that way.  

I subbed the Cointreau with Clement Creole Shrub, which seemed to fit the other ingredients well with an agricole base. As such, I didn't use a high-hogo rum, opting for Gosling's (given the Bermuda homage) and Cruzan Blackstrap. Used Domaine and Canton ginger, Regan's orange bitters. Excellent.

That is some sublime, gingery minty goodness. Disclaimer: I am hopelessly addicted to ginger and mint. Thank you for sharing!

Yes. Lord Hobo came up with a great intro to Fernet. It's fabulous (if you like Fernet, which I do).

Also tried with equal parts Fernet, ginger liquor, and gin, with great success.

Soothing

Added 2 dashes chocolate bitters. 👍

Curated this - because there was some confusion as to the proportions of this drink, I asked Julie Reiner and she sent me a picture of the recipe (which must be from The Craft Cocktail Party). Updated this to the specified brands - she's specific about them, changed 1 dash of Angostura to 2. Thanks,  Zachary

Should this be called "The Slope" rather than just "Slope"? That is the primary way I see it listed, and it refers to a neighborhood, so the emphasis would make sense here. There seem to be a LOT of slight variations of this cocktail including later versions (plural) attributed to Julie Reiner herself. There is a 2017 video by her using Maker's Mark bourbon (rather than rye) and Giffard Apricot--so it doesn't look like formula is set as one might expect. In various recipes on the web the base spirit is listed from 2 to 2 1/4 to 2 1/2 oz, while apricot is from 1/4 to 1/2 and Angostura bitters from 1 to 2 dashes.

I tried two different versions of this tonight based on a slightly different recipe and thought it was quite good (as did the others who sampled what I made.) I used "only" 2 oz of Rittenhouse Rye for both, with 3/4 Punt e Mes, and 1/4 R&W Apricot. This had plenty of peppery rye and alcohol heat which reinforced the bitter components in Punt e Mes. I used a single dash of Angostura for one, and a single dash of Abbott's bitters (my own bottling based on Darcy O'Neil's recipe) for the other.

The Angostura was pretty noticeable at only a dash, and this cocktail is a good candidate for experimenting with different aromatic bitters to appreciate the differences they provide. I somewhat preferred the cardamom/clove/fennel from the Abbott's over the more cinnamon baking spice of the Angostura, but others were evenly split as to preference.

I used J pear liqueur (60 proof) and not true eau de vie. Quite tasty, indeed; the maraschino didn't have a chance to dominate. Powerful sweet. The only real drawback I can see is the risk of diabetes. 4/5.

Yes, I would not substitute Pear Liqueur without re-designing the drink. It would be way too sweet for the amount of acid, and would overpower the other flavors, since Pear Eau-de-vie was a much more subtle flavor.

Not bad but the maraschino dominated some for us and as such the ginger and lemon juice were a little lost. Would probably tweak the ratios a bit. Beautiful color. 

Used closer to 1/4 Maraschino (Luxardo), with Pear Williams Purkhart Eau-de-Vie, and Canton for the ginger. the look is a bit like pink lemonade; the flavor is soft floral and fruity. I think a few extra dashes of Peychaud's only help make this drink better.

Maybe they're going for the citrus + spice thing?

Recipe updated based upon response from creator. Name and recipe changed.

basically a Gilroy with slightly different ratios?

Can't see this is in the Old Waldorf Astoria bar book.

The name "Tipperary Cocktail" is from Old Waldorf Astoria, but the proper credit for this particular version is Gaz Regan, who wrote the SF Gate article that is the referenced. From that article:

The earliest recipe I can find is in "The Old Waldorf-Astoria Bar Book," where author Albert Stevens Crockett declares that the drink predates the popular World War I song, "It's a Long Way to Tipperary." That particular ditty was penned in 1912, so we can probably surmise that the drink was created in the first decade of the 20th century. The formula, though, is pretty vile. I doubt that even a Yorkshire dweller - let alone a sturdy man from Tipperary - would put himself behind a glass full of sloe gin and dry vermouth with a little lemon juice.

Curated to clarify history and creator. Thanks @noksagt