Preheat oven to 350 degrees fahrenheit. Spray a 9x13 inch pan with non-stick spray.
In a large mixing bowl, whisk together cake mix, water, oil, and eggs, mixing until there are no lumps.
Pour into 9x13 pan, and bake cake according to box directions.
Allow the cake to cool.
Meanwhile, mix together lemon jello mix and boiling water. Set aside.
Take a fork, and poke lots of holes all along the cake.
Slowly pour jello over top of cake.
Cover tightly with foil, and move to the refrigerator to chill overnight.
Before serving, whisk together powdered sugar, lemon juice, and heavy cream.
Pour over the top of the lemon cake. Enjoy!