The Only Requisite is to Find a Post Cached Copy on Google or somewhere else.
- You need to Find the PostID of your Post
- Open Google in your Browser Window (here i will suppose is Firefox)
- Search for "yourBlogAddress.blogspot.com someKeywordsContainedInThePost"
- You should find your Deleted Post in the Search Results
- Look at the HTML Source: Firefox > View > Page Source
- Search for "postID"
- Mac Cmd+f
- PC Ctrl+f
- Copy the postID of the Deleted Post
- On Blogger Make a New Post
- Blogger > Posting > New Post
- Now Replace the postID with that of the Deleted Post
- Reload your Page on Browser
After You Should be Happy for the magically Restored Post ;)