Ramos Gin Fizz

1 egg white
1 1/2 oz heavy cream
1/2 oz fresh lemon juice
1/3 oz fresh lime juice
1/2 oz (2:1) simple syrup

3 drops vanilla extract

Combine and shake like the dickens for at least a minute. Then add:

2 oz Old Tom gin
3-4 drops orange flower water 

Shake like the dickens for another minute; strain into a tall glass; top with soda water; and add a straw.