In the chilled bowl of a stand mixer fitted with the whisk attachment, whip the heavy cream on high until soft peaks form. Add the powdered sugar, and continue whipping until stiff peaks form. Transfer whipped cream to a separate bowl and keep in the refrigerator.

Switch whisk attachment out for the paddle attachment. Beat the cream cheese on high until smooth and creamy. Add the sweetened condensed milk, beating until completely smooth. Add the lime zest, vanilla, salt, and half of the lime juice, beating until incorporated. Add the rest of the lime juice, and continue beating until completely combined. Fold in the whipped cream until just combined.

Pour filling into the crust, smoothing the surface with an offset spatula or a butterknife. Chill in the refrigerator, while you make the lime curd.

In a medium saucepan, whisk the egg yolks, whole egg, and sugar together until combined. Whisk in the lime juice, zest, and salt. Add the butter and cook over medium-low heat, stirring constantly, until the mixture has thickened, about 4-8 minutes minutes.

Immediately strain the curd through a fine-mesh strainer into a medium-size bowl. Cover with plastic wrap and place in the refrigerator to cool completely.

Once cooled, spread lime curd evenly on top of the cheesecake. Cover and refrigerate for at least 8 hours, preferably overnight.

Decorate with whipped cream and key lime slices. Slice, serve, and enjoy!