Preheat oven to 325 degrees. Grease 2 (8-inch) cake pans with coconut oil or spray with gluten free non-stick cooking spray. Place a circle of parchment paper in the bottom and grease it with oil or cooking spray.
In a large mixing bowl, whisk together the almond flour, arrowroot or tapioca starch, baking soda, cinnamon, and salt.
In another mixing bowl, combine the applesauce, orange zest and juice, agave, and vanilla. Add the wet ingredients to the dry ingredients and mix. Stir in the carrots and raisins. Divide the batter equally among the prepared pans, smooth the top, and bake for 40 minutes or until browned and a toothpick inserted in the center comes out clean.
Let cool in the pans for 15 minutes, then remove to a wire rack to finish cooling.
Frosting
Place the cashews in a bowl and cover with boiling water. Let sit for 30 minutes or up to an hour. (Alternatively, you can cover with cold water and refrigerate, covered, overnight.)
Drain the cashews and rinse with fresh water. Place in a blender with the orange zest and juice, agave, lemon juice, and coconut oil. Add 2 tablespoons almond milk and process until very smooth, scraping down the sides of the blender often. If needed to get to a spreadable consistency, add more almond milk and process.
To assemble, place one cake layer on a serving platter, top side down. Spread with a thick layer of frosting and place the second layer on top, top side up. Press the top layer down gently so that some of the frosting seeps out of the side of the cake. Spread the top with a thick layer of frosting. Refrigerate the cake until ready to serve.