• Preheat oven to 350ºF. Line a large baking tray with parchment paper and set aside.
• Bake hazelnuts on a small baking tray until golden and fragrant, about 5-8 minutes. Allow to cool a bit, then place in a clean towel and rub the skins off. Set aside.
• Add the bread flour, pastry flour, brown sugar and baking powder to the bowl of a stand mixer and combine using the paddle attachment.
• Cut the butter into cubes and add to the flour mixture. Continue to mix to a crumbly texture.
• Mix in the dark chocolate, milk chocolate and hazelnuts.
• In a separate bowl, lightly whisk together the eggs and vanilla bean paste to break up the eggs.
• Add the egg mixture to the flour mixture and mix just until dough has formed.
• Divide the dough into two pieces and shape into 24-inch logs on a parchment-lined baking tray. (see it here)
• Bake for 20-30 minutes and remove from oven. Lower oven temperature to 300ºF.
• Allow the biscotti to cool, then slice at an angle about ¾ inch thick with a large serrated knife.
• Return to the oven and allow them to dry for 15 minutes - a little longer if you like a really dry biscotti.
• Remove and allow to cool completely before dipping in the dark chocolate.

To make the dip:

• Place gianduja in a metal bowl over a pot of simmering water and melt to 45º.
• Remove from heat and stir in the dark chocolate until a working temperature of 29º - 30º is reached.
• Dip the biscotti and place on a parchment covered baking tray to set.