In a mixing bowl, combine graham cracker crumbs and melted butter. Press the mixture into the bottom of a baking pan to form the crust.
In another bowl, beat the cream cheese and sugar until smooth. Add eggs one at a time, beating well after each addition. Stir in vanilla extract, lemon juice, and orange zest.
Pour the filling over the crust and spread evenly.
Bake for 45 minutes or until the center is set. Let it cool completely before cutting into bars.