Slightly too sweet if you're looking for a Negroni but certainly interesting. I love how the hazelnut liqueur vanilla really brings out the chocolate from the bourbon. The venous tones and Campari keeps it from being cloying. Adding an orange peel could be an interesting addition.

I recommend adding a dash of vanilla bitters and/or chocolate bitters. Adds much more interest and complexity.

Topping this up with a couple ounces of tonic water makes for a particularly nice highballed Negroni variant.

GREAT drink, weird name. Ok, it’s from Munich; it’s a “Hazelnut Boulevardier,” what’s “Western” about it? The smell of dark chocolate (next time I’ll grate a little for more nose) works wonders with the hazelnut. Instead of Simon’s 2:2:2:1 ratio I used 6:3:2:2 (in quarter ounces) to tame the Campari and reduce the sugar. The hazelnut was subtle but discernible (could go 6:3:3:2) and it was still sweet and bitter enough. Maybe add cocoa bitters. I call my version “Boulevards of Munich.”

I didn't have dark chcolate at home and accompanies the drink with a pack of Toffifee (https://en.wikipedia.org/wiki/Toffifee) - caramel cups containing nougat, caramel and a hazelnut, topped with a chocolate button. I don't know about the availability of it outside Central Europe though. This was the perfect match. Of course you will largely exceed the nutrition value given here :-)

Gosh, have just tried this but with 100 proof Rye, Montenegro amaro, homemade Hazelnut Liqueur and Antica formula and it is scrummy. Thought I'd better write this before I have another.

Leon & Sander, may I ask how many drops of the orange bitters each of you employed? And, Calvin, what an interesting substitution!

Really enjoyed this, but possibly a touch sweet as is (as others have said)

Wow.

Haven't tried a Negroni I didn't like. This one was no exception. HAZELNUT negroni ! Like Andrew I was looking for something nice to do with Frangelico. Still want the bitter. Tried a few dashes Angostura Orange Bitters ; wasn't not an improvement but slight so I added about twelve dashes Regan's Orange Bitters. Interesting. What's that orange hazelnut confection? Immediately made another, this time with Punt e Mes rather than Antica Formula. Wow!

Very nice drink. I was looking for a good use of Frangelico. But, I think next time I might add a few dashes of orange bitters to up the bitterness and add a bit more complexity.