How to render HTML inside Slim templates

You want to disable HTML escaping for the link_to argument, not the entire link_to result. You're pretty close with your html_safe but your string interpolation is eating your "safe for HTML" flag. This should work better:

li= link_to '<i class="icon-user"></i> My Profile'.html_safe, current_user

This has been answered, but if you actually have some html and you want to render it in a slim template, use double equal.

== "<i>test</i>"

Will be the same as

= "<i>test</i>".html_safe