Preheat the oven to 350°F. Lightly grease a 9x13 inch baking dish with oil and set it aside.

In a large mixing bowl, add the cake mix, room temperature eggs, club soda, oil, and orange zest. Beat on medium speed for approximately 2 minutes until the mixture is smooth and fully incorporated.

Transfer the batter to your prepared baking dish and use a spatula to level the surface. Bake for 28-32 minutes until a toothpick comes out clean or with a few moist crumbs and the cake springs back when touched. Remove from oven and allow to cool on a wire rack or counter for exactly 1 hour.

During the cooling time, make the gelatin mixture. Add the orange gelatin to a medium bowl, pour in the boiling water, and stir continuously for about 2 minutes until fully dissolved. Stir in the cold water to combine, then let the mixture rest at room temperature while it cools slightly but stays liquid.

After the cake has cooled for 1 hour, take a fork or wooden skewer and pierce holes throughout the entire surface, keeping them about 2 inches apart. Press all the way down to the bottom of the pan to create deep channels. Gradually pour the gelatin mixture over the cake, distributing it evenly and allowing it to flow into all the holes.

Place the cake in the refrigerator and chill for 2-3 hours until the gelatin has completely set and feels firm when gently pressed.

Take the chilled cake out of the refrigerator. Using an offset spatula or butter knife, spread the chocolate frosting in an even layer across the top, creating decorative swirls for a festive appearance. Slice into squares and serve cold directly from the fridge.