Fernet "Milkshake"

1 12 oz Fernet Branca
34 oz Coffee liqueur, St. George (NOLA)
12 oz Crème de Cacao, Tempus Fugit
14 oz Bitters, Scrappy's Chocolate
34 oz Egg white
1 oz Cream
Whip shake all ingredients except cream with two cubes for approximately 30 seconds. Add cream, ice and shake again for approximately 15 seconds. Strain into either a coupe (the wash line will be right up to the lip on a 6 oz coupe) or a short Collins (< 10 oz) glass. I usually don't garnish, but you could do either some bittersweet chocolate gratings or a small pinch of espresso powder.
You could also go the flip route with this (replace the egg white and 1 oz cream with a whole egg and less cream). If you want something a bit sweeter, omit or reduce the chocolate bitters. Or swap out the Fernet Branca with Menta for a Grasshopper riff.
I've been making Fernet milkshakes for a few years using Fernet, espresso gelato, Guinness and chocolate syrup, and wanted to come up with a similar version that doesn't require ice cream, beer or a blender.