Preheat oven to 400 degrees and grease two 6-donut pans.
Mix all dry ingredients together in a large bowl (coconut flour, baking powder, salt, cinnamon and nutmeg).
In a seperate bowl mix the wet ingredients together (eggs, butter, honey and vanilla).
Add the wet ingredients to the dry ingredients and mix until well combined.
Fold in the carrots and most of the walnuts (save some walnuts for topping).
Spoon mixture into donut pans and bake for 10 - 12 minutes until the edges start turning golden brown.
Let cool for a few minutes in the pan before transfering to a cooling rack.
Mix all ingredients with a mixer. Top carrot cake donuts with cream cheese icing and walnut crumbles.