"kind of hard, dry bread baked in thin flat cakes," respelled early 19c. from bisket (16c.), ultimately (besquite, early 14c.) from Old French bescuit "biscuit" (12c.), altered under influence of cognate Old Italian biscotto, both from Medieval Latin biscoctum, literally "twice-baked," from Latin (panis) bis coctus "(bread) twice-baked;" see bis- + cook (v.). The U.S. sense of "small, round soft bun" is recorded from 1818.
<a href="https://www.etymonline.com/word/triscuit">Etymology of triscuit by etymonline</a>
Harper, D. (n.d.). Etymology of triscuit. Online Etymology Dictionary. Retrieved $(datetime), from https://www.etymonline.com/word/triscuit