This tutorial is about how to use cookies with CGI::Application.
First read the CGI::Application tutorial if you don't know the module works.
If you don't have done it before, check the documentation for CGI.pm:
# perldoc CGI
If you already know about CGI::Application, and knows how to use cookies with the CGI module, the only thing you have to do is to change $cgi->header for $webapp->header_props.