There are 3 options: two for all users, one for when you have the view deleted posts privilege, and if all fails you can only hope your browser history has still a link in its cache.
Find deleted posts in your profile
When the question or answer was posted less than 60 days ago you can find them in your profile:
- For questions: At the bottom of your question page click the deleted recent questions link
- For answers: At the bottom of your answer page click the deleted recent answers link
With the View deleted posts privilege
If you have the privilege Access to moderator tools you can search for your own deleted posts:
this will give you a search result similar to this:
Ask a moderator
If none of the options above work for you and it is really important to have that link you can ask a moderator to do a search for you. Don't go asking for links to all your deleted posts but provide a couple of search terms that should return a result to the best of your knowledge. You can reach out to a moderator by raising a custom flag on one of your posts, hop into a chat room that is also visited by moderators or post a request on Meta. Don't make this into a habit though.