Double Chocolate Pistachio Biscotti

~from Savoring Time in the Kitchen

2-1/2 cups all purpose flour, scoop and level method
1/2 cup bittersweet cocoa powder, such as Ghirardelli
1-1/2 teaspoons baking powder
1/4 teaspoon baking soda
1/2 teaspoon salt
3/4 cup (1-1/2 sticks) butter, just barely softened
3 teaspoons freshly grated navel orange zest (about 2 large oranges)
1 cup 
2 large eggs
1-1/2 teaspoon pure vanilla extract
1 cup whole salted pistachios
2 tablespoons finely chopped pistachios blended with 1 tablespoon granulated sugar
2 ounces shaved bittersweet chocolate
1 egg, mixed with 1 teaspoons water

Sift flour, baking powder, baking soda and salt.  Set aside.

In the bowl of a stand mixer with paddle attachment, mix butter and orange zest on medium high speed until smooth.  Slowly add 1 cup of sugar and beat for another minute.  

Add the eggs, one at a time, and beat for a minute each, scraping down the bowl.  Add vanilla and mix.  Reduce speed to low and add dry ingredients, slowly, mixing just until combined.  Do not over mix.

Remove bowl from mixer and fold in 1 cup of the whole pistachios and the shaved chocolate.  Cover bowl with plastic wrap and chill for 1 hour.

Preheat oven to 350 F. 

In a food processor, pulse the 2 tablespoons of pistachios with the 1 tablespoon of granulated sugar. 

Position oven shelves in upper and lower third of the oven.  Prepare 2 baking sheets with parchment or silicone liners.  

Divide dough into thirds, and on lightly floured surface, roll each piece into a 12 x 3 inch log (about 1 inch thick) and place on one of the baking sheets sideways.  All three should fit on one large baking sheet.  

Brush each with egg wash and sprinkle the tops with the chopped pistachio and sugar mixture.  

Bake for 25 minutes or until just lightly browned. Remove from oven and let rest on the pan for 5 minutes.  

Reduce oven temperature to 300 F.  Using a large spatula, carefully remove each log to a cutting surface and cut into 1 inch slices. Using 2 baking sheets, lay the slices on their sides and return to the oven for 15 minutes. Remove from oven and turn slices over.  Bake for another 7 to 10 minutes.  Allow to rest for 5 minutes and transfer to baking rack to cool completely.  

Can be stored in an airtight container for up to 3 weeks or freeze.