show a smarty variable with html content

You should try this:

{$html|unescape:'html'}

Also check manual:

http://www.smarty.net/docs/en/language.modifier.unescape.tpl

Interestingly, none of the answers here work with Smarty 3.1.21 on CS-Cart 4.3.4. So, just to add another thought in that circumstance, use the nofilter on the $html string like so:

{$html nofilter}