the word "biscotto", in this sense, shares its origin with the british-english (via old french) word "biscuit", which refers to what american-english-speakers call a "cookie". in modern italian, the word "biscotto" refers to any cookie or cracker, just as does the british use of the word "biscuit". (the number of bakings and the degree of hardness are not relevant to the term.) in north america, the term "biscotti", used as a singular, refers only to the specific italian cookie known in italy as "cantuccio".