Oyster Crackers - recipe needed

I like the old-fashioned kind which are like a round ball about an inch in diameter. Usually about as hard as rocks too. Does anybody have a recipe for them?

Did you see the recipe on Serious Eats? It may not be the rock-hard version from the grocery store, but looks like a close facsimile to the processed version:

“Food is a pretty good prism through which to view humanity.”

― Jonathan Gold

Market stall in Lima
Credit: TXMX 2