Preheat oven to 325 and line a baking sheet with parchment paper. Spread the coconut on top of the parchment paper and toast it for 5-7 minutes.
Pour the 1 cup of coconut milk beverage into a measuring cup and add 1 tablespoon of apple cider vinegar. Stir them together and let it sit for 5 minutes. Stir it again and add the toasted coconut and vanilla to the mixture. Let the coconut soak and soften it for about 10 minutes. Set aside.
Preheat the oven to 350 degrees and grease two 9-inch round cake pans with shortening.
In a medium bowl whisk together the flour blend, arrowroot, xanthan gum, baking powder, baking soda and salt.
In a large mixing bowl beat the oil, shortening and sugar together until combined using an electric mixer with paddle attachment for about 3 minutes. Mixture will look fluffy.
Add the eggs one and mix until combined.
With mixture on low alternate adding the flour mixture with the coconut/buttermilk mixture. Scrape down the bowl as needed and give the mixture a final stir using a spatula to ensure all of the ingredients on the sides and bottom of the bowl are incorporated.
Divide the batter evenly between the two prepared cake pans and bake 28-32 minutes until a toothpick inserted in the center of one cake comes out clean.
Let the cakes cool completely and make the frosting.