For the Cake

1. Preheat the oven to 350°F. Line the bottom of 2 8-inch springform loose bottom baking pans with a circle of parchment paper. Grease the parchment paper and the sides of the tins with butter.
2. Spread the walnuts across a sheet pan and toast in the oven for 3 to 5 minutes, until golden, then allow to cool.
3. Using an electric hand mixer, in a large mixing bowl, beat the eggs and the sweetener together until light and fluffy, about 2 minutes. Add the butter, cream cheese, and vanilla extract and mix again until well combined.
4. In a separate mixing bowl, combine all of the dry ingredients - almond flour, coconut flour, baking powder, cinnamon, ginger, nutmeg and sea salt. Mix until all ingredients are well incorporated.
5. Add the dry ingredients to the wet ingredients and mix until well combined.
6. Stir in the grated carrots and toasted walnuts.
7. Using a rubber spatula, spoon the batter into the 2 prepared baking pans. Use the spatula to smooth the tops. Bake for 30 to 40 minutes or until you can insert a toothpick into the center and have it come out clean. Check the cakes after 25 minutes and if the top is browning too quickly, loosely cover the cakes with tinfoil to prevent burning.
8. Allow the cakes to cool in the pans for 5 minutes, then remove them from the pans and allow them to fully cool on a wire rack. 

For the Frosting

1. Using a hand mixer, cream together the butter and the cream cheese until smooth.
2. Add the sweetener and the vanilla and mix until combined. Add cream, if needed, and beat again until smooth and creamy.
3. Add a layer of frosting on top of one of the cakes. Then add the other layer of cake on top and cover the top and sides with the remaining frosting. Top with chopped walnuts.