Preheat the oven to 350 F and prepare two 9-inch baking sheets by lightly greasing and dusting with flour.
Whisk together flour, baking soda, salt, cinnamon, allspice, and nutmeg.
In a separate, larger bowl, whisk together sugar and oil. Once blended, whisk in the eggs, one at a time. Add the flour mixture, then stir until blended. Fold in carrots, walnuts, ginger, and orange zest.
Divide batter between prepared baking pans. Bake until they pass the toothpick test, about 40 minutes. Remove from oven and cool in pans for 15 minutes, then turn out onto racks to let cool completely.