Preheat your oven to 350°F (175°C). In a mixing bowl, combine the orange cake mix with eggs, vegetable oil, and orange juice, and stir in the orange zest.

Pour the batter into a greased 9x13 inch pan or divide between two round cake pans. Bake for 25 to 30 minutes.

Let the cake cool in the pan for about 10 minutes, then transfer to a wire rack to cool completely.

In a mixing bowl, combine the instant vanilla pudding mix with cold milk and whisk until thick. Fold in the whipped topping and cream cheese if using.

Once the cake is cool, spread the frosting generously over the top and between layers if using two pans.

For decoration, add fresh orange zest or candied orange slices on top before serving.