Preheat your oven to 350 degrees
Grease two 9 inch rounds and line the bottom of each pan with parchment paper
With a large mixing bowl or a KitchenAid mixer combine the cake mix, half of the jello mix, and 12 ounces of the sparkling water. (I got the key lime sparkling water from Walmart)
Once the batter is combined, divide into the two pans and bake for 20-22 minutes
Once the cake is done baking, take it out and let it cool for at least 1 hour
The lining of the pan with parchment paper will make it easy to remove these from the pan with no casualties or cake breaks!
Once the cake is cooled, place the first layer onto a cake plate.
Use about ΒΌ of the frosting to top the bottom layer and top with some fresh lime zest (optional but recommended)
Carefully place the second cake layer on top, make sure that it is aligned and looks pretty!
Use the remaining frosting to cover the cake
Top with more fresh lime zest!
Serve and enjoy :)