Add vanilla extract, lemon juice, and simple syrup to the shaker.
Fill the shaker with ice cubes.
Shake vigorously for 15-20 seconds.
Strain the mixture into a tall glass filled with fresh ice.
Top with club soda.
Garnish with a pear slice and mint leaves.
Notes
Store extra pear mixture in an airtight container for up to 24 hours.To make ahead, prepare the pear mixture and store it separately from the club soda.Add more simple syrup if the pears aren't sweet enough.For best results, use ripe Bartlett or Anjou pears.The drink tastes best when served right away while the bubbles are fresh.