These biscotti draw from the flavors in baklava with pistachio and rose water. I know this sounds crazy, but I actually enjoy shelling and then skinning roasted pistachios - it's just so relaxing to keep your hands busy and let your mind wander. If you're pressed for time, buy pre-shelled pistachio and get going. If you'd like, you can up the rose water but another 1/2 to 1 teaspoon.
I adapted this recipe from one for Tuscan biscotti di Prato in Lou Seibert Pappas’ book "Biscotti." Like all authentic biscotti (or at least the way I've learned to make them), these contain no shortening. —zahavah
pistachios in their shells (or 1 cup pistachios without shells), divided
Remove the pistachios from their shells. You should end up with about one cup (assuming you don’t eat too many).
Skin the pistachios. Fill a bowl with the pistachios and cover them with boiling water. Let them sit for about 3 minutes until the water is cool enough for you to reach in and pluck out a few pistachios at a time. Squeeze them between your fingers and the skins should slip right off. This step also removes the salt.
Spread the pistachio on a cookie sheet in a single layer. Toast in the oven for 7-10 minutes until they’re dry and fragrant. Let them cool.
Chop the pistachios with a knife or pulse a few times in a food processor. You should still have chunks, not a fine powder. Put the nuts aside.
In a bowl, whisk together the eggs, rose water, and sugar (I use my stand mixer). Add the baking soda, salt, and flour and mix until everything is blended. Mix in 3/4 cup of the pistachios.
Cover a baking sheet with parchment paper or aluminum foil. Shape the dough into two long, skinny loaves (about 15 inches long and 2 inches wide). They will spread a lot during baking, so make sure to leave enough room between them. Sprinkle with the remaining 1/4 cup chopped pistachios and a few pinches of turbinado sugar. Bake for 40 minutes until firm and golden brown.
Let the loaves cool for about 5 minutes until you can touch them. Lower the oven to 275ºF.
Slice the loaves on the diagonal into 1/2- to 3/4-inch wide slices.
Lay the slices flat on the baking sheet (you may need two) and bake for 10 minutes. Remove the sheet(s) and flip the slices over. Continue baking for another 5 minutes.
Store the biscotti in an airtight tin or jar. I usually put half of them directly in the freezer to save myself from them.