Preheat oven to 350 degrees. Line a baking sheet with parchment or a silicone baking mat. Gather ingredients so that you have everything close at hand on the counter or table.
Prepare the Ingredients
Using a cutting board and knife, chop the dried cherries into small bits.
With a nut chopper, coarsely chop the shelled pistachio nuts. Set aside until ready to use.
In a large mixing bowl, cream together the softened butter and granulated sugar until creamy. Beat in large eggs and vanilla extract.
Mix the Dough
In a small bowl, combine all-purpose flour, baking powder, and salt. Gradually mix into the beaten egg mixture. Dough will be sticky.
Add in the chopped pistachios and dried cherries. Scoop the dough onto the prepared baking sheet and pat it into a flattened log about 13 inches long, 3 inches wide, and about 3/4" thick.
Wet the end of an offset spatula, and smooth out the top and sides. Sprinkle with decorating sugar, if desired.
The First Bake
Bake for 25 minutes a preheated oven. Remove the baking sheet from the oven. Reduce oven temperature to 325 degrees.
Spray the log with water, spritzing the sides and top. This will soften the crust just enough to make slicing easier.
Wait five minutes, then cut crosswise with a sharp knife (such as a Santoku) into 1/2" slices. Place cookie slices on baking sheet standing up on bottom edge, with space between each cookie.
The Second Bake
Bake for another 30-35 minutes, until biscotti feel very dry and are golden around the edges. Remove from oven and transfer to a rack to cool. Makes 2 dozen.
Notes
*Unless otherwise indicated, all butter used on this recipe site is salted.