Preheat oven to 350°F. Line a large, rimmed cookie sheet with parchment paper. Set aside.
In a small bowl whisk together flour, cornmeal, ginger, baking powder, and salt. Set aside. In the bowl of your stand mixer, beat sugar, oil, eggs, vanilla, and about a teaspoon (or slightly more to taste by about 1 teaspoon, if desired) fresh zest of an orange until very smooth, about 2 minutes.
Reduce the mixer speed to medium low and gradually add in the flour mixture. Dough will be very stiff. Add in the pistachios and cranberries.
Flour both hands. Working directly on the prepared baking sheet, scrape the dough onto the parchment-lined baking sheet. Shape into a 12x4-inch-long log that is approximately ¾-inches thick. Flatten the top slightly.
Bake until lightly golden and the top begins to haze and crack, about 35 to 38 minutes, rotating the pan halfway through the baking time. Remove from the oven leaving the oven on and allow the log to cool directly on the baking sheet for 15 minutes.
Remove the log carefully to a sturdy cutting board. Use a long-serrated knife to slice the log into ½-inch-wide slices. Place the slices cut-side-down onto the same parchment-lined baking sheet and bake again for 8 minutes before flipping and baking for another 8 minutes. the biscotti will be golden in color.
Cool the biscotti directly on the baking sheet, about 45 minutes. Then remove each cookie carefully to a wire rack to harden for about an hour prior to dipping in chocolate.