Prepare the pie filling: In a large bowl, combine cream cheese, sweetened condensed milk, lemon zest, and lemon juice. Using an electric mixer on medium, mix until smooth.
Add filling to crust: Spread into pie crust and smooth top. Refrigerate for 7 hours (or until set).
Add topping and zest: Once the pie is set, pull it out and top it with a layer of homemade whipped cream , and sprinkle with additional lemon zest, if using.
