Vegan Dark Chocolate Blood Orange Layer Cake (gluten free)

Vegan Dark Chocolate Blood Orange Layer Cake (gluten free)
Makes 1 6 inch 4 layer cake

2 6 inch cake pans

Cake:
1 1/2 cups all purpose gluten free flour (or gluten free oat flour)
1/3 cup cacao powder
1 cup coconut sugar
1 1/2 tsp baking soda
1 tsp baking powder
1 tsp sea salt
1 cup pureed apple
1/4 cup virgin olive oil
1 Tbsp pure vanilla extract
2 Tbsp orange zest
1/4 cup + 2 Tbsp fresh blood orange juice at room temperature
2 Tbsp apple cider vinegar

Frosting:
2 cans organic full fat coconut milk, chilled
2 cups raw cashews, soaked for at least 4 hours in water and drained
2/3 cup blood orange juice
2 Tbsp blood orange zest
3/4 cup raw coconut nectar, maple syrup or agave nectar
1/2  tsp sea salt
2 tsp pure vanilla extract
1 2/3 cups coconut butter, warmed to liquid
2/3 cup raw cacao butter, warmed to liquid**

Preheat the oven to 375 degrees and position rack in center of oven. Line two six-inch-diameter cake pans with 2-inch-high sides with parchment paper. Coat parchment paper and pan sides lightly with coconut oil so that the cake doesn't stick and line the bottom of the pan with a piece of parchment fit to the pan.
Whisk flour, cacao powder, baking soda, sea salt, sugar in a large bowl to blend well.
Whisk apple puree, oil, vanilla, orange zest and juice together in small bowl to blend well, then whisk into the flour mixture until well blended. Whisk in the cider vinegar until bubbles form.
Transfer cake batter to prepared pans and bake cakes until tester inserted into center comes out clean, about 25-30 minutes.
Cool cakes completely in pan on rack, about 1 hour. Cut around sides of pan to loosen. Turn cakes out onto platter; peel off parchment paper. Let cool completely, then place in the fridge to chill until very cold to make slicing easier. When chilled, slice cakes horizontally in half so that you have 4 layers.