Sending an unescaped cookie

Hello:

In my controller, I am writing a cookie and then immediately redirecting
to an external site, as such:

cookies[:foo] = {:value => ‘http://example.com’}
redirect_to ‘https://example.org

The site I am directing too looks for the URL set in the foo cookie in
order to redirect back to my site. However, the cookie that is written
is escaped so that it looks like http%3A%2F%2Fexample.com. Thus the
external application considers that the URL of an improper format. Is
there any way to send the cookie as an unescaped string?

Thanks