Creating your Ice Cream Sandwich Cake is easy. Follow these straightforward steps:

1. Prepare a Cake Pan: Use a 9×13-inch cake pan and line it with parchment paper, leaving some overhang to make removal easier.
2. Layer the Sandwiches: Place the first layer of ice cream sandwiches in the pan, fitting them tightly for a solid base. Cut some sandwiches if necessary to make them fit snugly.
3. Spread Ice Cream: Scoop the chocolate ice cream and spread it evenly over the layer of sandwiches. Use a spatula to smooth it out.
4. Add Hot Fudge Sauce: Drizzle a generous amount of hot fudge sauce over the chocolate ice cream layer.
5. Add More Sandwiches: Place another layer of ice cream sandwiches on top of the hot fudge sauce. Press down lightly.
6. Spread Vanilla Ice Cream: Add the vanilla ice cream over this layer, smoothing it out just like the chocolate.
7. Add Whipped Topping: Use the whipped topping to create a creamy layer on top of the vanilla ice cream.
8. Final Toppings: Sprinkle the crushed cookies and rainbow sprinkles all over the whipped cream for a festive look.
9. Cover and Freeze: Cover the pan with plastic wrap or aluminum foil. Place it in the freezer and freeze for at least 4 hours or overnight for best results.
10. Slice and Serve: When ready to serve, carefully lift the dessert out of the pan using the parchment overhang. Cut into squares and plate.

These steps will guide you through making a splendid Ice Cream Sandwich Cake that everyone will love.