html wont render using ng-bind-html-unsafe

Question

i was able to break string to chars array and surround each char in <span></span> but when im trying to pass this array to table the html wont render. breaking the string:

//parse cron_format and edit each digit individually
$scope.parse = function (cron_format){
    var parsed = cron_format.split('');
    for(var i = 0; i < parsed.length; i++) {
        parsed[i] = '<span>' + parsed[i] + '</span>';
    }
    return parsed;
}

when i try to create the table like this:

<table class="table table-bordered table-hover">
    <thead>
        <td>user name</td>
        <td>script name</td>
        <td>cron format</td>
    </thead>
    <tbody ng-repeat="(user_id,script_id) in data  | filter: test">
        <tr ng-repeat="(script_id, cron_format) in script_id">
            <td>{{user(user_id)}}</td>
            <td>{{script(script_id)}}</td>
            <td ng-bind-html-unsafe="{{parse(cron_format)}}"></td>
        </tr>
    </tbody>
</table>

there are no values in cron_format: without trying to render -> <td>{{parse(cron_format)}}</td>

the table looks like this: what am i doing wrong?

UPDATE:

i changed function's two last rows :

$scope.parsed.htmlSafe = $sce.trustAsHtml(parsed.html);
return parsed;

and i get this error:

Can't interpolate: {{parse(cron_format)}}
TypeError: Cannot set property 'htmlSafe' of undefined

can someone explain whats the mistake im doing here?