Sort by "last modified"

Hi there,
I wanted to ask if there is a possibility to include a sorting filter “last modified”, to show posts in the widget sorted by when they were last updated…

This would be great, as a lot of content is frequently updated although the post date might be quite old.

There is a post here but somehow I can’t get this to work.

http://petercoughlin.com/tweaking-the-genesis-featured-posts-widget/

Also, I would prefer to stick to your widget for reasons of consistency..

Thanks!

http://wordpress.org/plugins/genesis-featured-widget-amplified/