etymology lesson for the day: biscuits
biscuits comes from the latin - "bi" meaning two and "cuits" meaning cooked. so it roughly means "cooked twice".
most people don't put together the italian "biscotti" with "buscuits" - but of course the two words are pretty much cognates.
ever see how you cook biscotti? you cook them once in a loaf, cut them into slices, and cook them again. yep, you cook them twice.