Preheat oven to 375 degrees. Generously spray 2 – 9 inch round cake pans with gluten-free, non-stick cooking spray. Cut circles out of parchment paper and line the bottom of the cake pans with the parchment and lightly spray it with some more cooking spray.
In a food processor fitted with a steel blade combine the almond flour, ½ cup Sucanat and orange zest and process for 30 seconds to combine and grind a little. If you do not have a food processor, you can skip this step and just whisk it all together but if you use the food processor the cake will have a finer texture.
Separate the egg yolks and whites into two large mixing bowls. Beat the egg whites until they form stiff, glossy peaks. In the mixing bowl with the egg yolks add the remaining half cup of Sucanat and salt and beat on high speed until thick and almost doubled in size - about 2 minutes. Stir in the almond mixture. Take a large spoonful of the beaten egg whites and mix into the yolk mixture and then gently fold in the remaining whites until the mixture is no longer streaky and is well combined. Divide the batter among the prepared pans and bake for 25 – 30 minutes or until golden brown and a toothpick inserted in the center comes out clean. Let cool in the pans for 5 minutes then remove to a cooling rack to finish cooling. While the cake is cooling, make the frosting.
In the bowl of an electric mixer, preferably fitted with a whisk attachment, beat the coconut oil for 1 minute. Add the powdered sugar and the vanilla and turn the mixer on low. Add the orange juice, 1 tablespoon at a time, until the mixture reaches the consistency of butter cream frosting - creamy and spread-able but not too thin. Increase the speed of the mixer to medium-high and continue to beat for 5 minutes.
To assemble the cake, place one layer of fully cooled cake, top-side down, on a cake stand or platter. Tuck a few small strips of waxed paper under the edges to keep the platter clean while frosting. Spread some frosting on top of the cake then top with the remaining cake layer, bottom side down. Frost the sides and the top of the cake. Gently press the sliced almonds into the frosting around the sides of the cake. Chill the cake for about 30 minutes then remove the strips of waxed paper. Garnish the top of the cake with sugared orange zest if desired.
Sugared Orange Zest
Combine 1 cup water with 1 cup sugar in a small saucepan. Bring to a boil then add the orange zest. Let boil gently for 15 – 20 minutes or until the zest is tender. Place the remaining ½ cup of sugar on a plate. Carefully remove the zest from the liquid and drop into the sugar, tossing to coat. Let the zest dry in the sugar and the remove. Can be made several days ahead and stored in an airtight container at room temperature. Do not throw out the sugar water the zest was cooked in, it is terrific stirred into iced tea.