In a mixing bowl, combine cookie mix, butter, egg, and 1/2 cup chocolate chips. Stir to form dough. Drop by rounded tablespoons onto ungreased cookie sheet. Bake in preheated oven for 10 to 14 minutes. Cool for 1 minute on cookie sheet before transferring to wire rack. Cool cookie completely, and then freeze for a minimum of 1 hour before completing ice cream sandwiches as directed.
Soften ice cream on the counter for 10 minutes prior to making sandwiches. Remove cookies from freezer, place a scoop of ice cream on the backside of 1 cookie. Sandwich with another cookie and carefully press together until ice cream reaches the edge of the cookies. Roll edges in remaining chocolate chips. Freeze for 10 minutes, then serve.