Basic custom Page Template in Genesis

page_custom_content.php

<?php
/*
	Template Name: My Custom Page
*/

# Remove the entry content
remove_action( 'genesis_entry_content', 'genesis_do_post_content' );
# Add custom entry content
add_action( 'genesis_entry_content', 'rr_do_post_content' );

/**
 * Outputs custom post content
 *
 * @return void
 */
function rr_do_post_content() {

	// Put your custom content here
	echo 'Hello Robin';

}

genesis();