Preheat oven to 350F, cover cookie sheets with parchment paper or baking mat.
In a large bowl add, butter, sugar, and mix until well combined. Add egg, JELLO, and mix. Add flour and mix until there is no flour.
Roll into 1 inch balls and bake for 13-15 minutes
To make the ice cream, in a large bowl, mix together half and half, sweetened condensed milk and vanilla extract. Freeze overnight or use ice cream maker.
To make the ice cream sandwich, place ⅛ cup of ice cream on cookie, drizzle caramel on ice cream, then cover with another cover. Slowly press together and freeze once more for 15-20 minutes.