Walnut Cookie and Caramel Ice Cream Sandwiches

For my Aunt Mardo’s eightieth birthday party, I made caramel ice cream to serve with both a double-chocolate layer cake and a strawberry crème fraîche cake, (if you can’t have two cakes when you’re eighty, when can you have them? And we had to have room for all the candles.) The next day, we had leftover caramel ice cream but no cake, so for lunch I put together these ice cream sandwiches. The important part of making caramel ice cream is getting the caramel cooked to the p