Zend 2 variable from controller to layout.html

Zend 2 variable from controller to layout.html

I am new Zend 2. I succeed to pass data to my viewmodel, but now I want to
pass a var to my layout.phtml
How can i do that?
controller:
<?php
namespace Pages\Controller;
use Zend\Mvc\Controller\AbstractActionController;
use Zend\View\Model\ViewModel;
class IndexController extends AbstractActionController {
function indexAction() {
return new ViewModel(array(
'data' => 'home'
));
$this->layout()->setVariable('myVariable', 'Value');
}
}
layout.phtml:
$test = $this->myVariable;
echo $test;