Preheat oven to 350 degrees F. Line two 9-inch cake pans with parchment paper and generously spray with nonstick cooking spray. The parchment paper makes it easy to remove the cakes from the pan. Tip: I recommend turning the pans upside down and placing parchment paper on top. Use a pencil to trace the cake pan, then cut out the outline with a scissors and place parchment in each pan. Spray with nonstick cooking spray.
In a large bowl, whisk together oat flour, almond meal, baking soda, cinnamon, nutmeg and salt. Set aside.
In the bowl of an electric mixer (or you can mix by hand), add in carrots, eggs, maple syrup, almond milk, vanilla extract, coconut oil and apple cider vinegar. Beat on medium low speed until ingredients are well combined and smooth.
Add in half of the dry ingredients and mix on low speed until combined.
Add in the other half of the dry ingredients and mix on low speed again until just combined. If desired, fold in any of the following with a wooden spoon: raisins, coconut, nuts or chopped pineapple.
Divide batter evenly among the two prepared cake pans and smooth top with a rubber spatula. Bake for 23-27 minutes or until toothpick inserted in the middle comes out clean with just a few crumbs attached.
Cool cake in the pans for 30 minutes, then invert cakes on a wire rack, removing from the pans and allowing to cool completely. At this point you can remove and discard the parchment paper.
Once cakes have cooled completely (about 2 hours), you can prepare the frosting. In a medium bowl, beat cream cheese until smooth and creamy. Slowly add in powdered sugar, vanilla and cinnamon and mix on low speed until well combined.
Divide frosting in half and spread over each cake. Once frosted, place one cake on top of the other and sprinkle with extra pecans and coconut, if desired. Serves 12 (12 large slices).