Preheat the oven to 325.
Put the walnuts and figs in a food processor fitted with the chopping blade, and pulse for about 30 seconds, until finely chopped.
In the bowl of a stand mixer, fitted with the paddle attachment, mix the butter, granulated sugar and brown sugar together on medium high speed until pale and fluffy, about 3 minutes. Add the eggs, one at a time, and the vanilla extract and orange zest. Scrape down the sides of the bowl as needed.
In a medium bowl, whisk together the flour, baking powder, baking soda, spices and salt. Add the flour mixture to the mixer bowl and beat on medium low speed for a few seconds until just incorporated.
Add the fig and walnut mixture and mix until combined. Scrape the dough out onto a sheet of plastic wrap, shape into a ball, and chill for about 20-30 minutes
Turn the dough out onto a baking sheet lined with parchment paper or a silicone baking mat. For large biscotti, shape the dough into one log, about 9 x 4 inches (it should be about 3/4 inch thick). For smaller biscotti, shape into two logs, about 9 x 2 inches. Set the logs at least 2 inches apart on the baking sheet because they will spread while baking. Sprinkle the logs with granulated or coarse turbinado sugar for some sparkle.
Bake the logs in the preheated oven for about 25 minutes. Remove from the oven and let scool for 5 minutes. Spritz logs with water and let sit again for five minutes. This will soften the dough just a bit to make it easier to slice.
Remove the logs to a countertop and slice them with a serrated bread knife into about 3/4 inch cookies. A straight up and down motion works better than a sawing motion in my experience.
Place the biscotti back on the baking sheet, separating them a little and return to the oven for another 20-25 minutes, or until dry (smaller cookies will need a little less time, so keep an eye on them.
Cool completely before eating, storing or packaging.