For the Baileys espuma, whisk the melted chocolate with the egg and yolk over steam until frothy. Slowly add Baileys and whipped cream and then strain through a fine sieve.
Pour into a 0.5 L iSi unit. Screw on an iSi cream capsule and shake vigorously. Chill the Baileys Espuma for at least 1 hour.
Preparation Tip:
For a 0.25 L iSi unit, halve the ingredients.