This was my first attempt at making biscotti, recipe recently turned up and passed around and tweaked here and there but this is the one I made mine from, it was a huge hit by everyone who had them!
They go really good with coffee and tea or with a glass of milk.
Preheat oven to 350 degrees F and line two baking sheets with parchment paper. In a standing electric mixer fitted with paddle, (I do not have a standing mixer but a hand held one) beat the butter and sugar at medium speed until creamy. Add the eggs, vanilla seeds and rum and beat until smooth.
In a small bowl whisk the flour with cocoa powder, baking powder, salt and cinnamon. Add the dry ingredients to the batter and beat at low speed until incorporated. Beat in the whole pistachios. ( I first used whole but coarsely chopped is a little easier to work with)
Divide the dough into 4 pieces. On a lightly floured surface roll each piece into about a 1 inch to 1 1/2 inch thick log. Place two logs on each baking sheet at least 3 inches apart and press to flatten slightly. Then brush the logs with beaten egg white.
Bake logs for approximately 25 minutes. The tops should be cracked and glossy and slightly firm to the touch. Remove from oven and let logs cool slightly. (5-10 minutes) Using a sharp chef's knife, cut the logs into approx 1/3 inch thick diagonal slices. Arrange the slices on the baking sheets and bake for an additional 20 minutes, until dry.
Let cool completely; If you choose to melt chocolate for dipping you will need to follow instructions for melting chocolate. After dipping one end in the chocolate you can sprinkle lightly with the chopped pistachios. Place on cookie sheet with wax paper and refrigerate until the chocolate is set.