Source of new Twig templates

[CJDennis]

When the Create Template shortcut is used, where does the template come from? Every one of my templates starts off as

{% extends '@HMRXApp/Layout/email.layout.html.twig' %}

{% block body %}

{% endblock %}

{% block header %}

{% endblock %}

The header and body are always the wrong way around. Is there any way to control how templates are created?