In a medium bowl, whisk the flour, cinnamon, baking soda, nutmeg, ginger, and salt. In a large bowl with a hand mixer or in a stand mixer fitted with the paddle attachment, mix the oil, eggs, carrots, brown sugar, walnuts, raisins, and vanilla on medium speed until well blended, about 1 minute. Add the dry ingredients and mix on low speed until just blended, about 30 seconds. Divide the batter evenly between the prepared pans.