Gather ingredients, spray 2 9-in cake pans with baking spray, and preheat the oven to 350°F (180°C).
In a medium bowl, whisk flour, baking soda, salt, and cinnamon in a until very well blended.
In a large bowl, using an electric mixer, or the whisk, mix the oil, granulated sugar, brown sugar, and vanilla. Add the eggs, one at a time, mixing after each one.
Slowly add the dry ingredients into the large bowl. Carefully incorporating everything until the batter is smooth. Stir in carrots, nuts, and raisins.
Divide the cake batter between the prepared cake pans. Bake until the tops of the cake layers are springy when touched and when a toothpick inserted into the center of the cake comes out clean, 32 - 38 minutes.
Remove the cakes from the oven, and leave them in the pans for 15 minutes, then carefully turn the cake layers out onto cooling racks. Cool completely before frosting.