Preheat oven to 350 F (175 C). Grease 8-inch cake pan with cooking spray. Line with parchment paper. Spray with cooking spray over the parchment paper. Set aside.
For the cake layers:
In a food processor process walnuts and 1/3 cup SPLENDA® Brown Sugar Blend until fine crumbs are formed.
Beat egg whites until soft peaks. Carefully fold the walnut sugar mix into the egg whites. Divide batter into 4 equal parts. Bake each cake layer for 12-15 minutes. Carefully remove from the cake pan and peel of the parchment paper. Let them cool down to room temperature.
For the chocolate ganache:
In the meantime prepare the ganache.
In a medium sauce pan over low heat melt butter. Add cocoa powder and whisk to incorporate, making sure there are no lumps.
In the bowl of an electric mixer with paddle attachment beat egg yolks and 1/3 SPLENDA® Brown Sugar Blend for 3-5 minutes until thick and frothy. Beating on low speed, add the cocoa butter mixture. Beat until incorporated. Beating on low, slowly add the heavy cream to thin the ganache. Let it cool completely.
To assemble the cake:
Place a cake layer on a plate. Spread about 1/4 cup of the ganache over it. Cover with another layer. Spread 1/4 cup ganache over it. Repeat with the remaining layers. Cover the cake with chocolate ganache. Place cake in the fridge uncovered for at least 1 hour to set.
You can decorate the top of the cake with chopped walnuts, almonds or shredded coconut. The original recipe calls for green colored chopped almonds, but I colored some shredded coconut in green and used it to top the cake.