Preheat the oven to 170 degrees Celsius. Line round cake tin with baking paper.
In a large mixing bowl sieve buckwheat flour, mixed spice, cinnamon and baking powder. Add coconut sugar and almond meal and whisk lightly to combine.
In a medium sized mixing bowl whisk together the eggs, olive oil, honey and carrot.
Pour wet ingredients as well as chopped walnuts into dry ingredients and stir through until just combined.
Pour cake batter into baking paper lined cake tin and into oven to bake for one hour, or until cake springs back when pushed down gently in the centre.
Once cake is cooked, remove from oven and allow to cool in tin for 5 minutes before transferring to cooling rack.
Cashew Cream Cheese Frosting
Add the soaked cashews, maple syrup, lemon juice, coconut cream, lemon zest and water to a high speed blender. Blend on high until mixture is smooth and creamy.
Using a frosting tool, spoon or the back of a butter knife, spread the cashew cream cheese over the top of the carrot cake. Serve topped with extra walnuts and lemon zest if desired.
Cashew Cream Cheese
The recipe yields enough cashew cream cheese frosting to frost the top and sides of the cake or to frost the top plus a layer (if you wish to create a layer cake). If you are only wanting to frost the top of the cake then you can halve the recipe. Coconut cream is not essential to this recipe but does make the cream cheese more smooth and creamy. Leave out if you don't have any on hand.
Storing the Carrot Cake
Store this carrot cake in the fridge. If you choose to frost the cake you can store in the fridge for 2-3 days and then transfer to the freezer.