Preheat oven to 350 degrees F. Grease a 8- or 9-inch cake pan and line the bottom with parchment or waxed paper.
In a mixing bowl, combine the almond flour, brown sugar, coconut oil, cocoa, almond extract, salt, and egg yolks. Mix thoroughly.
In a large bowl, beat the egg whites using an electric mixer on high speed until soft peaks form. Gently fold the egg whites into the batter, adding one-fourth of the mixture at a time. (The batter will be very thick) Transfer the batter to the prepared cake pan.
Bake for 35 to 40 minutes, or until a toothpick inserted in the center comes out clean. Cool in the pan for 15 minutes.
Run the tip of a thin knife around the edge to loosen the cake from the pan. Invert the pan on to a serving plate and remove the paper. Serve plain with fresh berries, or top with brown sugar icing
MAKE THE BROWN SUGAR ICING
Combine all ingredients except almonds in a bowl and mix with an electric blender until smooth.
Frost the top of the cake with icing, and top with sliced almonds.