MetaBehavior.php

<?php
namespace App\Model\Behavior;

use Cake\ORM\Behavior;
use Cake\ORM\Query;
use Cake\Utility\Hash;

class MetaBehavior extends Behavior
{

    public function findMeta(Query $query, array $options)
    {
        $query
            ->contain([
                'Meta' => function ($q) {
                    return $q->hydrate(false);
                }
            ])
            ->formatResults(function ($results) use ($options) {
                $results = $results->map(function ($value, $key) {
                    if (!empty($value['meta'])) {
                        $value['meta'] = Hash::combine($value['meta'], '{n}.key', '{n}.value');
                    }
                    return $value;
                });

                return $results;
            });

        return $query;
    }
}