large-favicon.php

<?php

/**
 * Large Favicon
 *
 * @author Bill Erickson
 * @see https://www.billerickson.net/code/large-favicon/
 *
 * @param string $url, favicon image url
 * @param int $size, size in pixels
 * @return string $url
 *
 */
function ea_large_favicon( $url, $size ) {

	if( intval( $size ) >= 128 ) {
		$favicon_id = 88; // uploaded to media library
		$url = wp_get_attachment_image_url( $favicon_id, array( $size, $size ) );
	}

	return $url;
}
add_filter( 'get_site_icon_url', 'ea_large_favicon', 10, 2 );