In a shot glass, pour Kahlua to fill approximately ¾ of the glass.
Hold a spoon upside down just over the shot glass. Gently, pour Baileys over the spoon, allowing it to float on top of the Kahlua.
Notes
It's important not to dump the Bailey's into the glass, so be gentle. The Bailey's is lighter than the Kahlua, so it will rest on top, resembling a pint of Guinness.