From handlebarsjs.com :
Handlebars HTML-escapes values returned by a {{expression}}. If you don't want Handlebars to escape a value, use the "triple-stash".
<div class="entry">
<h1>{{title}}</h1>
<div class="body">
{{{body}}}
</div>
</div>
with this context:
{
title: "All about <p> Tags",
body: "<p>This is a post about <p> tags</p>"
}
results in:
<div class="entry">
<h1>All About <p> Tags</h1>
<div class="body">
<p>This is a post about <p> tags</p>
</div>
</div>
However from my point of view it may defeat the purpose of having a template separated than you're js file.
If you use precompile then use noEscape option:
handlebars.precompile(content, {noEscape: true})