In a heatproof bowl, combine the orange gelatin powder with boiling water. Whisk until completely dissolved. Set aside to cool to room temperature, approximately 30 minutes.

Lightly coat a 9-inch springform pan with nonstick spray. Line the bottom and sides with parchment paper for easier removal.

In a mixing bowl, combine graham cracker crumbs, melted butter, and salt. Stir until the mixture resembles wet sand. Press evenly into the base and slightly up the sides of the prepared pan. Transfer to the freezer for a minimum of 30 minutes.

In a large bowl, use an electric mixer to beat softened cream cheese with 1 cup of powdered sugar until smooth and creamy (about 2 minutes). Set aside.

In a separate bowl, whip the heavy cream with the remaining ½ cup powdered sugar, vanilla extract, and orange zest (if using) until stiff peaks form.

Gently fold half of the whipped cream into the cream cheese mixture until fully incorporated. Fold the remaining whipped cream into the cooled orange gelatin mixture in a separate bowl.

Alternately spoon the cream cheese mixture and the jello mixture into the chilled crust, creating visible layers. Use a butter knife to gently swirl the two mixtures together for a marbled effect.

Cover the cheesecake with plastic wrap and refrigerate for at least 6 hours or overnight, until completely firm.

Remove the sides of the springform pan. Garnish with additional whipped cream or orange slices, if desired. Slice with a sharp knife and serve chilled.