How can I pull data from a field in the CMS and insert into the form function finish()?

I have the fields setup and my MultiForm is on this page...

<?php

class MenuOrderForm extends Page {
	
	private static $db = array(
	      'MenuFormMailTo' => 'Text',
	      'MenuFormSubject' => 'Varchar(200)'
	);

   function getCMSFields() {
      $fields = parent::getCMSFields();

      $fields->addFieldsToTab('Root.Form', array(
         new Textfield('MenuFormSubject', 'Email Subject'),
         new Textfield('MenuFormMailTo', 'Email to (BCC): (if multiple addresses, separate with a comma)')
      ));

      return $fields;
    }

}

class MenuOrderForm_Controller extends Page_Controller {

   public static $allowed_actions = array(
      'MenuMultiForm'
   );
   
}

MultiForm...

<?php

class MenuMultiForm extends MultiForm {
	
	public static $start_step = 'MenuOrderInfoFormStep';

	public function finish($data, $form) {
		parent::finish($data, $form);

		$steps =  MultiFormStep::get()->filter(array(
		   "SessionID" => $this->session->ID
		));
		$output = array(); 
		foreach($steps as $step) { 
			$output = array_merge($output, $step->loadData()); 
		}
		
		$from = 'email@domain.com'; 
		$to = $output['ContactEmail'];
		$subject = 'Menu Order Form Submission'; 
		
		$email = new Email($from, $to, $subject); 
		
                 // How Pull MenuFormMailTo from MenuOrderForm.php and insert in Bcc?
		$email->addCustomHeader('Bcc', '       '  ); 
 
		
		$email->setTemplate('MenuEmail');
		$email->populateTemplate($output);
		$email->populateTemplate($data);
		$email->send();
		$controller = $this->getController();
	        $controller->redirect(Director::get_current_page()->Link() . "?menu-success=1");
		$this->session->delete();
		
	}

}