Cookie Editor

This extension offers a toolbar button to view and edit all the cookies that are related to the current page. Note that this extension also lists those cookies that are accessed by subframes located on the current page. Cookies are categorized into different sections based on their origins.

It is possible to edit different cookie properties right from the popup. Also, you can delete the selected cookie as well.

For bug reports please use
https://github.com/joue-quroi/cookie-editor/