Is there a way to use Dvorak keyboard layout, but with command keys mapped to qwerty?

This is called "Dvorak - QWERTY command" on Mac, and it is useful. I have found this a autohotkey script for windows which claims to do what you want, but I haven't tested it.

This also seems to be a dupe of a stackoverflow question, which suggests you can use the Microsoft Keyboard Layout Creator to do it as well.

I wrote a tool that implements the "Dvorak-Qwerty command" layout on Windows, and even another one for Unix. You can get them here:

Dvorak-Qwerty ⌘" (DQ) keyboard layout for Windows and Unix/Linux/X

I guess this is a "third-party app" from your point of view, but I haven't been able to find a better solution.