Shake all but the bitters with three ice cubes and strain into a pilsner glass. Fill the glass with crushed ice until it cones over the top. Garnish with the bitters.
This is the first drink I've posted that's not my own. I felt compelled because it's an excellent and extraordinary-looking drink and I wanted to share the photo. BTW, I crush ice by holding it in my hand and smacking it with a bar spoon, so the results are chunky and inconsistent.