Editing the menu bar via CLI

I'm looking to automate the setup of settings/configuration of my Pi's via Ansible and I'm trying to find out which file(s) to edit to add and remove pinned applications on the menu bar. Perhaps I'm searching the wrong terms, but I've only found the .layout files which don't seem to specify the menu bar items, just the overall layout. Any push in the right direction of where to look would be much appreciated!