Beat eggs whites until frothy. Then gradually add the remaining egg and sugar and continue to beat. Add orange juice, orange zest, Cointreau, and oil and beat until well mixed.

In a medium-sized bowl, stir together all the dry ingredients, including walnuts, fresh and dried cranberries, and then gradually add this to the wet ingredients. The dough will be on the wet side.

Divide the dough into two or three long logs, attempting to make them of equal size and place on a cookie sheet lined with a piece of parchement paper. Remember that the logs will expand; provide about three inches between them. Sprinkle the sugar, if desired, on top of the dough.

Bake for about 15 minutes at 325ºF. Let logs cool on a wire rack.

Once the logs are cool, slice them on a diagonal – approximately 1⁄2″ thick and place them on the cookie sheet. Crisp, as desired, in oven at 350ºF for about 10-15 minutes, turning biscotti over after about seven minutes. Remove from oven and let cool. Store.

Optional frosting:  If you like, drizzle with a light frosting of confectioner’s sugar, orange juice, and orange zest.