For the cake:

1. 1. Preheat your oven to 350°F (175°C). Grease and line two 8-inch round cake pans with parchment paper.
   2. In a medium bowl, whisk together the almond flour, cocoa powder, baking powder, and salt.
   3. In a separate large bowl, whisk together the eggs, sugar, applesauce (or oil), vanilla extract, and milk until smooth and fully combined.
   4. Gradually add the dry ingredients to the wet ingredients, mixing until just combined. Be careful not to overmix to maintain a light texture.
   5. Divide the batter evenly between the prepared cake pans, smoothing the tops with a spatula.
   6. Bake for 25-30 minutes, or until a toothpick inserted into the center comes out clean. Allow the cakes to cool in the pans for 10 minutes before transferring to wire racks to cool completely.
2. For the chocolate orange buttercream:
   1. In a large bowl, beat the softened butter with cocoa powder until smooth and well combined.
   2. Gradually add the powdered sugar, one cup at a time, beating well after each addition.
   3. Add the orange zest, heavy cream, vanilla extract, and orange juice, then beat on high for 2-3 minutes until the buttercream is light, fluffy, and smooth.
   4. Taste and adjust the orange flavor by adding more zest or juice if desired.
3. Assembling the cake:
   1. Once the cakes have cooled completely, place one layer on a serving plate or cake stand.
   2. Spread a generous layer of the chocolate orange buttercream over the top of the first cake layer.
   3. Place the second cake layer on top and spread the remaining buttercream over the top and sides of the cake, smoothing it with a spatula.
   4. Optionally, garnish the cake with additional orange zest, chocolate shavings, or sliced almonds for a decorative touch.
   5. Refrigerate the cake for 30 minutes to set the buttercream before serving.