In a large mixing bowl, combine all dry ingredients, except the cherries and hazelnuts, and stir together. In a smaller bowl, mix together the wet ingredients, and stir together.
Add the wet ingredients to the dry ingredients, and stir until just combined.
Add the cherries and roughly chopped hazelnuts (I chop them almost just in half, so the chunks show up in the slices of biscotti), and fold in.
Chill the dough for 1 hour. This step is important for preventing the almond flour from over browning, and keeping the dough for spreading out too much during baking.
Preheat oven to 340 degrees F. A slightly lower baking temperature than typical is important to keep the almond flour from over browning.
Take the chilled dough, and on a lined baking tray, form into a log about 1 1/2 inches high and 6 inches across.
Bake the cookie log for 20 minutes. Once baked, allow to cool for about 20 minutes, and then freeze for about an hour before slicing.
Preheat the oven to 190 degrees F.
Take the chilled or frozen loaf, and slice into thin slices. If you'd like crunchier biscotti, try to cut about 18 slices (3/4 an inch), or if you'd like a chewier biscotti, as few as 13-14 slices.
Bake biscotti slices for 18 minutes. Open the oven door for about a minute after it finishes baking to allow the heat to escape, and then leave the biscotti in the oven for an additional 10 minutes to crisp up completely.
Once the biscotti has cooled, drizzle it or dip it into melted dark chocolate and then grate orange zest over the top before the chocolate hardens.
For best results, store biscotti in the fridge for up to 3 weeks, or the freezer wrapped tightly for up to 3 months.