Cranberry Ice-cream Squares With Chocolate-cookie Crust

In a food processor grind the cookies fine and pat half the cookie
crumbs firmly into the bottom of a 9-inch-square baking pan lined
with plastic wrap. In the large bowl of an electric mixer beat the
ice cream with the paddle attachment until it is softened, add the
cranberry sauce and the Grand Marnier, and beat the mixture until it
is just combined. Spread the ice-cream mixture over the crust,
sprinkle the top with the remaining cookie crumbs, and pat the cookie
mixture, covered, for 6 hours, or until it is firm, invert a platter
over the pan, and invert the pan onto the platter. Unmold the dessert
onto the platter, discarding the plastic wrap, and cut it into
squares with a serrated knife.