Undefined variable with laravel and blade

I know it's probably super simple, but I just started using laravel today, I've always been on codeigniter before. The problem I have is that laravel tells me that my variable is not defined ...

Controller:

public function index()
{

    $data['pageTitle']='Connexion';

    return view('login')->with($data);
}

The line concerned in login.blade.php:

@extends('layout.header', $pageTitle)

Error:

"Undefined variable: pageTitle (View: G:\Winginx\home\laravel\public_html\resources\views\login.blade.php)"

Thanks !

via Chebli Mohamed