Boil the four cups of water. After it reaches a hard boil, add the lime Jello and gelatin and mix well until everything is dissolved. Add the ice cream and mix until the ice cream is melted.
Pour into a 9x13 pan and put in the refrigerator to cool.
Let set for about 4 hours but overnight is best.
When completely set, cut with desired cookie cutter and take out of the pan with a spatula. Refrigerate until ready to serve. Make sure to eat the leftovers!