Not to say that it doesn't exist but I can't imagine a crisp biscuit / cookie that you could cleanly slice with a guitar cutter. A water jet would probably do the job perfectly. Don't know if they sell small scale water jets for hobbyists / small business.
Update, just did a search and a desktop waterjet does exist.
https://wazer.com/waterjets/desktop/
And here are a few that are built for the food industry. https://www.waterjetcorp.com/en/products/gourmet/
