The name biscotti is derived from 'bis' meaning twice in Italian and 'cotto' meaning baked or cooked. Great for dunking in coffee or tea.
What could be a proper ratio for an Italian biscotti recipe?
It probably is Two parts flour to One part sugar.
Then what about oil or Butter?
In a Classic Italian biscotti no butter or oil is added. And back-in-the day, when eggs were used it was enough eggs to make the batter stiff.
Though modern biscotti are associated with the Tuscan region of Italy. Tuscan biscotti were flavored with almonds from the plentiful almond groves of Prato. Italians call biscotti cantucci, and use the term biscotti to refer to any type of crunchy cookie, round, square and otherwise as the British use the word biscuit.