Jack's Manual by J. A. Grohusko (1910, p.62)

1 dashAngostura bitters base
1 ponyBenedictine modifier
1 ponykummel modifier
1 yolkegg yolk other
  1. Build the bitters, yolk, Benedictine, and kummel carefully in a pony glass.
  2. Serve without mixing the layers.

Ice: None

Preserve the distinct layers rather than stirring.

The Buffet Blue Book by John H. Considine (1912, p.39)

0.33 sherry wine glassraspberry cordial base
3 dropsAbbott's Bitters bitter
0.33 sherry wine glassBenedictine modifier
0.33 sherry wine glasskummel modifier
1 yolkegg yolk other
  1. Layer the raspberry cordial, egg yolk, Benedictine, kummel, and Abbott's Bitters in a sherry wine glass as for a pousse cafe.
  2. Keep the colors separate and serve.

Ice: None

Layering is central to the identity.

See also: Jersey Lily Pousse Cafe, Brandy Scaffa

Source says to prepare it as one would a pousse cafe so the colors keep separate.