Pulse vanilla wafers in food processor until finely chopped.
Add 3/4 cup sugar and the melted butter.
Pulse until incorporated.
Grease bottom and sides of 9" spring form pan.
Press mixture firmly into bottom and slightly up sides of the pan.
Place in freezer for 30 minutes to firm up.
Beat cream cheese and remaining sugar until well blended.
In a medium bowl, combine the gelatin and boiling water.
Whisk until the gelatin is dissolved. Set aside.
Zest a lime and set aside.
Whip heavy cream, powdered sugar and vanilla until stiff peaks form.
Add half of the whipped cream mixture to cooled gelatin and add the lime zest.
Whisk until blended. Set aside.
Fold remainder of whipped cream mixture into cream cheese mixture.
Spread half of the cream cheese mixture over crust.
Pour 2 cups of lime whipped cream mixture over cream cheese mixture.
Gently spread remaining cream cheese mixture over lime mixture.
Pour remaining lime whipped cream mixture over plain cream cheese mixture.
If desired, take a butter knife and gently glide through cream cheese layers to swirl.
Refrigerate for at least 6 hours.
You can optionally garnish with whipped topping and cherries