In a medium mixing bowl, combine the graham cracker crumbs, granulated sugar, and melted butter. Stir until crumbly and press into a 9-inch pie dish. Chill for at least 30 minutes.

In a large bowl, beat softened cream cheese until smooth. Gradually mix in sweetened condensed milk, lemon juice, and lemon zest. Mix until homogeneous.

In a separate bowl, whip heavy whipping cream until stiff peaks form. Gently fold into the cream cheese mixture.

Pour filling into the chilled crust, smoothing out the top. Cover with plastic wrap and refrigerate for at least 4 hours until set.

Before serving, garnish with extra lemon zest or whipped cream. Serve chilled.