Preheat the oven to 325F and grease a 9-inch springform pan well.
In a medium bowl, whisk together the almond flour, cocoa powder, coconut flour, whey protein, baking powder, instant coffee and salt.
In a large bowl, beat butter with sweetener until well combined. Beat in eggs, vanilla extract. Beat in half of the almond flour mixture and then beat in the water. Add remaining almond flour mixture and beat until fully combined.
Spread the batter in the prepared baking pan and bake 30 minutes or until just firm to the touch. Remove and let cool completely.
Chocolate Mousse Layers:
Follow the directions for the Blender Mousse recipe, adding the xanthan gum in to the blender with the chocolate, cocoa powder, and sweetener. This will help set your mousse a little more firmly.
Pour the chocolate mousse mixture over top of the cooled cake in the pan and chill at least 2 hours, until set.
Follow the directions for the white chocolate mousse (times 2!) and spread over the chilled chocolate mousse layer. Chill again for an hour or two, until firm.
Run a sharp knife around the inside of the pan before loosening the springform sides. Decorate with shaved chocolate or chocolate shards, if desired.
Cut into slices with a heated knife (heat under hot water).
Serves 16. This is a big, rich cake! Each serving has 3.48g NET CARBS.Food energy: 293kcal Total fat: 25.94g Calories from fat: 233 Cholesterol: 108mg Carbohydrate: 6.03g Total dietary fiber: 2.55g Protein: 6.32g