In a mixer, combine the ice cream, cranberries, sliced almonds, and pecans.
Cover the bottom and edges of a cake mold with plastic wrap.
Place the chocolate biscuits at the bottom of the mold. Pour half of the ice cream over the biscuits. Spread the crushed biscuits. Pour the remaining ice cream.
Close the plastic wrap over the preparation and place in the freezer overnight.
The next day, remove the mold from the freezer. Remove the plastic wrap from the top of the ice cream log. Flip the log onto a serving plate.
Sprinkle the top of the log and the serving plate with powdered sugar. Arrange the half-macarons around the log.
Serve immediately or put back in the freezer until serving time.