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Much obliged, Ed. Most recipes call for two whole eggs and two egg whites. I was going to substitute four egg whites and skip the yolks to see what would happen. Since biscotti are twice baked (hence the name!) they are dry anyway and the unctuous nature of the yolks is probably lost, this may turn out undetectable.

Next batch will be with almonds, dried cherries and fennel or anise seeds.

P.S. Latest batch of whites came from eggs used to make buttermilk ice cream (one of my faves).

CRISP CHOCOLATE BISCOTTI
FROM PERFECT LIGHT DESSERTS (MORROW, 2006) BY NICK MALGIERI AND DAVID JOACHIM
This is a streamlined version of an excellent biscotti recipe shared by my friend, cake designer Ellen Baumwoll. Adding some nuts to the dough increases calories, but provides a bit of much-appreciated richness in what would otherwise be a plain cookie.
Makes about 60 biscotti, about 44 calories each
1 3/4 cups all-purpose flour (spoon flour into dry-measure cup and level off)
2/3 cup alkalized (Dutch process) coca powder
2 teaspoons baking powder
1/2 teaspoon salt
1 1/4 cups sugar
2/3 cup (about 3 ounces) walnut pieces, coarsely chopped
6 large egg whites
2 teaspoons vanilla extract
Two cookie sheets or jelly roll pans covered with parchment or foil
Set a rack in the middle level of the oven and preheat to 350 degrees.
Sift the flour and cocoa into a medium mixing bowl. Stir in the baking powder, salt, sugar, and nuts.
Whisk the egg whites and vanilla together and add to the dry ingredients. Use a large rubber spatula to stir the dough together. At first the dough may seem dry, but as the sugar continues to melt, the dough will become softer, and eventually quite sticky.
Scrape the dough out onto a lightly floured surface and press it together. Divide the dough into 2 equal pieces and roll each to a cylinder the approximate length of the pan you are using. Arrange the two pieces of dough on one pan (the other will be used later for toasting the biscotti). Make sure the pieces of dough arenít too close to each other or to the side of the pan. Press each down to flatten it with the palm of one hand.
Bake the logs of dough for about 30 minutes, or until they are well risen and firm when pressed with a fingertip. Leave the oven on and place racks in the upper and lower thirds.
Cool the baked logs on the pan on a rack.
After the logs of dough have cooled completely, use a sharp serrated knife to cut them into 1/2-inch straight or diagonal slices.
Arrange the slices, cut side down, on the prepared pans and return them to the oven to toast for about 15 minutes.
Cool the toasted biscotti on the pans on racks.
Serving: Very good on their own, they certainly do a lot to dress up a plain sherbet or ice milk.
Storage: Keep the biscotti between sheets of wax paper in a tin or plastic container with a tight-fitting cover.