Preheat the oven according to cake mix package instructions. Prepare the cake batter by combining the orange cake mix, orange soda or juice, vegetable oil, and eggs in a mixing bowl. Mix well.
Pour the batter into a greased cake pan and bake according to package directions. Allow the cake to cool completely.
In another bowl, prepare the filling by mixing the instant vanilla pudding mix with cold milk. Stir in the optional orange extract. Fold in the whipped topping until well combined.
Once the cake is cool, cut it in half horizontally. Spread the filling between the layers and on top of the cake.
Garnish with orange zest or slices and white chocolate shavings if desired.
Notes
For an added twist, try using different citrus flavors in the cake or filling.