Combine the graham cracker crumbs, melted butter, and sugar in a bowl until evenly moistened.
Press the mixture firmly into a 9-inch pie dish, covering the bottom and slightly up the sides. Refrigerate while preparing the filling.
Beat the softened cream cheese until completely smooth.
Gradually mix in the sweetened condensed milk until combined
Add the fresh lemon juice, lemon zest, and vanilla. Mix until smooth
In a separate bowl, whip 1 cup heavy cream with 2 tablespoons powdered sugar until medium-stiff peaks form
Gently fold the whipped cream into the lemon mixture in several additions
Spoon the filling into the chilled crust and smooth the top
Cover and refrigerate for at least 4 hours, or preferably overnight
Before serving, whip the remaining heavy cream with powdered sugar and vanilla. Spread or pipe it over the chilled pie
Garnish with fresh lemon zest and optional lemon slices
Slice with a sharp knife and serve cold
