The easiest way to modify the template is to edit the template for a single item of the blog posts widget. Edit->Single Item Settings tab -> check the "Full blog post item" template. There you can insert your own control or html.
the Telerik team
Do you want to have your say when we set our development plans? Do you want to know when a feature you care about is added or when a bug fixed? Explore the Telerik Public Issue Tracking
system and vote to affect the priority of the items