gistfile1.txt

        $options = Mage::getModel('sales/quote_item_option')
            ->setItemId($item->getId())
            ->getCollection()
            ->getOptionsByItem($item);
        foreach($options as $option){
            if($option->getCode() == "info_buyRequest" && $buy_request = $option->getValue()){
                $buy_request = unserialize($buy_request);
                if(isset($buy_request['custom_options']['cake'])){
                    //cake is found in the custom_options of a buyRequest
                }
            }
        }