Preheat oven to 325 degrees and grease an 8-inch cake or springform fan. Set butter and coconut or palm oil shortening out on counter to come to room temperature.
In a large bowl, whisk together eggs, orange juice and zest, oil and extracts. Fold in cake mix until well combined.
Transfer to greased pan with a spatula, smoothing top. Bake atop a sheet pan for 30-35 minutes, rotating once 180 degrees halfway through cooking, until the cake bounces back when pressed.
Cool for 10 minutes then loosen cake from sides of pan and invert on a wire cooling rack. Cool completely in the refrigerator before halving and icing.
While cake is baking, make the Chocolate Orange Frosting. In a large bowl, first add the cacao powder and arrowroot followed by the softened butter, coconut or palm oil shortening, honey, orange juice and zest, salt and vanilla. Begin on low and working up to high, beat ingredients until fluffy, 1-2 minutes, careful not to let cacao and arrowroot fly everywhere. The frosting should be smooth and glossy.
Chill frosting until cake is completely cooled- you can bring it back to room temperature to warm up for 15-20 minutes if it gets too cold.
To assemble cake, begin by using a serrated knife to gently cut the cake in equal halves horizontally. On a cake stand, add bottom cake layer. Add a little less than half of the frosting, smoothing evenly. Top with second layer of cake, (rounded end facing down). Add remaining frosting on top, smoothing evenly. Top with candied orange slices in the middle, and chocolate shards around the perimeter. Slice and serve.
Make sure to store leftovers in the refrigerator overnight as this cake recipes contains no preservatives.