TSK · Leviticus 6:21

If your offering is a grain offering made on the griddle, it must be choice wheat flour mixed with olive oil, unleavened.

As for any clay vessel they fall into, everything in it will become unclean and you must break it.

Mattithiah, a Levite, the firstborn son of Shallum the Korahite, was in charge of baking the bread for offerings.