Preheat your oven to 350°F (175°C).

In a medium bowl, combine graham cracker crumbs, melted butter, and sugar until well mixed.

Press the mixture firmly into the bottom of a greased 9×9 inch baking pan to form the crust.

Bake the crust for 10 minutes, then remove from the oven and let it cool.

In a large mixing bowl, whisk together the orange juice, orange zest, sugar, and eggs until smooth.

Stir in the heavy cream and vanilla extract until fully combined.

Pour the filling over the cooled crust and bake for an additional 25-30 minutes, or until the filling is set and slightly jiggles in the center.

Allow the bars to cool completely at room temperature, then refrigerate for at least 2 hours before slicing into squares.