In a mixing bowl, combine crushed peanut butter cookies with melted butter until the mixture resembles wet sand. Press firmly into the bottom of a 9-inch cake pan to form an even layer. Set aside to firm up.

Scoop the chocolate ice cream into the prepared crust, spreading it evenly. Smooth the top with a spatula and freeze for about 1 to 2 hours until solid.

After the chocolate layer is firm, scoop the peanut butter ice cream onto the chocolate layer, spreading evenly. Return to the freezer for another 1 to 2 hours.

Once final freezing is done, remove the cake from the freezer. Spread whipped cream on top and drizzle with caramel sauce.

Slice the cake into squares or scoop into bowls, and serve immediately.