Thought this would be appropriate tonight, since it is Tales week.
1.5 oz gin
0.5 oz lemon juice
0.5 oz lime juice
1.5 oz simple syrup
2 oz cream
0.75 oz egg white
4 or 5 drops (no more) orange flower water
Dry-shake the ingredients, then add ice and shake for a long, long, long time (start softly to avoid shattering the ice too much) - at least 1 minute, ideally 2, to fully emulsify the ingredients.
Strain into a highball glass and top the foam with some soda water to create extra head.
Yum!
BTW you have to see Chris McMillan in action on this and the Mint Julep: