Magento – add custom block inside minicart

Erfan is right that the html is outputted twice, once as a child of 'checkout.onepage.login' and once as a child of 'checkout.onepage.billing'

Thus there are two child blocks with the same name. Each can have a different template, and each gets rendered as a child of the parent.

To change the persistent block in either of the parent blocks, you need to target the parent block directly such as:

<checkout_onepage_index>
    <reference name="checkout.onepage.login">
            <block type="persistent/form_remember" name="persistent.remember.me" template="my/custom/template.phtml" />
        </reference>
</checkout_onepage_index>

The above will only change the template in the login block.

If you only target the child block 'persistent.remember.me' then magento seems to only change the occurrence of the first found block. Start Speculation: This is most likely in order or alpha occurrence , with 'checkout.onepage.billing' appearing alphabetically before 'checkout.onepage.login', in whatever array is used to store the block internally. The fact that .billing is rendered after .login just makes it look like it is only changing the second occurrence. :) End Speculation

I just tried this way and works for me:

 <?php echo $this->getLayout()->createBlock('checkout/cart_crosssell')->setTemplate('checkout/cart/crosssell.phtml')->toHtml();?>

Add this code in header.phtml or other file where you want to show the crossells

<div class="top-panel mini-cart pp-shopping-block" data-role="pp-shopping">

      // Calls the mini cart
      <?php echo $this->getLayout()->createBlock('checkout/cart_sidebar')->setTemplate('checkout/cart/sidebar.phtml')->toHtml();?>

      // Calls Cross-Sells
      <?php echo $this->getLayout()->createBlock('checkout/cart_crosssell')->setTemplate('checkout/cart/crosssell.phtml')->toHtml();?>

</div>