Preheat the oven to 350°F. Line two 8" cake pans with parchment paper.
In a medium bowl, whisk together the oat flour, almond flour, baking powder, baking soda, cinnamon, ginger, nutmeg allspice, and salt. Set aside.
In a large bowl, whisk together the applesauce, maple syrup, nut butter, apple cider vinegar, ground flaxseed, and vanilla.
Slowly stir the dry ingredients into the wet.
Fold in the carrots, raisins, walnuts, and pecans.
Divide the batter evenly between the cake pans. Bake 25-30 minutes until a toothpick inserted into the center of the cakes comes out clean and they are starting to turn golden.
Remove from the oven and let cool completely on a cooling rack.
Meanwhile prepare the frosting. Using a hand mixer or stand mixer, beat the frosting ingredients until combined and slightly fluffy. Refrigerate until ready to use.
When the cakes are cooled, use an offset spatula to spread half of the frosting on top of one cake. Then top with the second cake. Spread the other half of the frosting on top.
Decorate with some chopped pecans and walnuts. Serve and enjoy!