Add Featured Post Gadget / Widget in Blogger Blog
1. Go to Layout section of the blog and click on Add a Gadget and then select Feature Post gadget from the popup window, as shown in below image:
2. Then the following window will appear and then just choose Label from the drop down list and then choose the particular post in that label to show in Featured Post widget as shown in below image:
You are done, it will now show the Featured Post in your blog.