In a mixing bowl, combine the graham cracker crumbs and melted butter.

Press this mixture firmly into the bottom and up the sides of a 9-inch pie dish.

In a separate bowl, beat together the softened cream cheese and powdered sugar until smooth.

Gradually mix in the lemon juice and vanilla extract.

Fold in the sweetened condensed milk gently until completely combined.

Pour the lemon filling into the prepared crust, spreading it evenly.

Cover the pie with plastic wrap and refrigerate for at least 4 hours.

Once set, remove the pie from the refrigerator and garnish with lemon zest if desired.

Slice the pie into wedges and serve chilled.