Powershell: force set-content to write UTF-8 with BOM?

Hi!

I'm trying to get powershell to use UTF-8 with a BOM.

Normally, when I create a new file, set-contents -encoding UTF8 works fine. However, when the file already exists and has no BOM, no BOM gets written.

Can I make powershell emit the BOM no matter what?

Lots of Greetings!