I know when you type in your NAKED domain (domain without WWW) to Blogspot, you will see a red strip with white text which says: THERE ARE ERRORS ON THIS FORM.(as shown below).
And in the Advanced Settings, below Your Domain box, you will see this:
"Blogs may not be hosted at naked domains (ex: yourdomain.com). Please add a top-level domain (www.yourdomain.com) or subdomain (blog.yourdomain.com)."
Here is a tutorial on how to host Blogger with naked domain.
1. Instead of just typing in your naked domain in the Your Domain box, you leave an empty space, then only you type in your naked domain.
In other words, press your space bar (from your keyboard) once then only you type in your naked domain name.
2. Type in the characters accordingly for Word Verification.
3. Click SAVE SETTINGS.
4 Now you can see a small tick-box with "Redirect www.yourdomain.com to yourdoamin.com" below your naked domain name. Click or tick the box.
5. Now click SAVE SETTINGS.
6. That's all.