Magento Cart Items – Getting Child Product Items

This is how it’s done in the Mage_Checkout_Block_Cart_Item_Renderer_Configurable class. It will return the simple product if available otherwise it will return the product of the cart item.

<?php
public function getChildProduct()
{
    if ($option = $this->getItem()->getOptionByCode('simple_product')) {
        return $option->getProduct();
    }
    return $this->getProduct();
}