Using an electric mixer, beat the whipping cream until stiff peaks form. Set aside.
1/2 cup (125ml) whipping cream
Using the same mixer, beat together the cream cheese and sugar.
8 oz (1 block) cream cheese, 3 Tbsp granulated sugar
Mix in the condensed milk, key lime juice, and lime zest. Add in the whipped cream and mix again until smooth.
10 oz (1 can) sweetened condensed milk, 1/2 cup (125ml) key lime or lime juice, 1 Tbsp lime zest
Pour over prepared crust and smooth the surface. Chill uncovered in the refrigerator for a minimum of 6 hours or best to let it set overnight.
Garnish with some more whipped cream and key lime slices if desired.
Notes
Leftovers can be covered up and stored in the fridge for up to 3 days. You can make this recipe from 6 hours to 2 days in advance. Cover after the next day.