Bring cream cheese to room temperature.
Whisk together cream cheese, lime juice, zest, powdered sugar and vanilla extract.
In a separate bowl, mix heavy cream and 1/4 cup powdered sugar. Reserve 1/3rd of the sweetened whipped cream for topping.
Fold cream cheese mix and whipped cream mix together until smooth. The texture should look like a mousse.
Use a cupcake scoop to scoop a single scoop of filling into 6 mini graham crusts.
Pipe reserved 1/3rd whipped cream mix on top of the cheesecakes.
Slice some key limes and add 1 thin slice for garnish. Sprinkle with a little zest on top if deserved.