Is it possible to display HTML content in a smarty variable, that is escaped using escape:HTML?

I have a smarty variable in *.tpl that cannot be changed:

{$some_value|escape:'html':'UTF-8'}

I have to assign a new value for this variable in PHP. This new value contains some basic HTML:

$some_value = '<span>'.$val.'</span>';

Is it possible to get is parsed as HTML somehow?

I know that it is definitely better to include all HTML tags in tpl and not in PHP, but in this particular case tpl cannot be edited.