Line a 9x13-inch baking dish with aluminum foil for easy lifting.
Place a single layer of ice cream sandwiches tightly in the bottom of the dish.
In a separate bowl, blend the softened chocolate ice cream with the whipped cream until smooth and creamy.
Spread half of the chocolate mixture evenly over the layer of ice cream sandwiches.
Drizzle half of the caramel sauce over the chocolate layer.
Sprinkle half of the crushed graham crackers and walnuts (if desired) on top.
Repeat the process by adding another layer of ice cream sandwiches.
Add the remaining chocolate ice cream mixture on top.
Top with the rest of the caramel sauce, crushed graham crackers, walnuts, and sprinkles (if using).
Wrap the dish tightly with foil and place it in the freezer for a minimum of 4 hours or until solid.
When ready to serve, take it out of the freezer and let it sit for about 10 minutes before slicing into squares.