Bake cake according to the directions on the box using a 9x13 pan.

While cake is baking, dissolve lime jello mix in boiling water.

Add 1/2 c. cool water after dissolved and let cool to about room temperature.

After cake has been baked, cool 5 minutes.

Punch holes in cake with the small end of a wooden spoon. A grid of holes about 2" x 2" will be fine, you don't want to completely mash up the cake :-)

Pour the room-temperature lime jello mixture over the top of the cake, filling in the holes.

Mix the instant pudding, milk and cool whip together in a bowl to a creamy/frothy consistency.

Frost the cake with this mixture and then place in the fridge for a couple of hours to firm up the jello.