WP Genesis: Add external link on Post Title

functions.php

<?php

// Filter post title
// to add custom url, just add a custom field with name ExternalURL and url as value  where you want the title to go when clicked
add_filter( 'genesis_post_title_output', 'jay_post_title_output', 15 );

function jay_post_title_output( $title ) {

	if ( is_singular() && get_post_meta( get_the_ID(), 'ExternalURL', true) )
		$exturl = get_post_meta( get_the_ID(), 'ExternalURL', true);
		$title = sprintf( '<h1 class="entry-title"><a href="%s" title="%s" target="_blank">%s</a></h1>', $exturl, get_the_title(), get_the_title() );

	return $title;

}