First, prepare the syrup. The Revani rule says: Cold syrup goes on the hot cake! It would be good to prepare the syrup a night before and keep it in the room temperature.
Place the water, stevia, orange peel strips and cinnamon sticks in a deep pot. bring it to a boil.
Mix gelatine with 50 ml water and add it to the syrup. Let it simmer for 8 minutes. Remove from heat and let it cool down. Add lemon juice when the syrup is cold.
Beat the eggs with butter, stevia, and baking soda. Add lemon juice, vanilla and beat for 3 more minutes.
Combine coconut flour, ground almonds and coconut flakes and add this mixture spoon by spoon to the egg mixture. Keep mixing at high speed.
Grease the 30 cm baking sheet or cake mould with some butter and pour in the cake batter.
Bake at 180ºC for 25 minutes. When the cake is baked, using a ladle, pour the syrup all over the cake. Try to add it to the corners first, and very slowly in the middle in order to preserve the cakes hight. Take a sharp knife and stub the cake in several places so that it "drinks" the syrup.
When the cake cools down place it in the refrigerator. Before serving, cut the cake in rectangular shapes, add some crushed pistachio, coconut flakes and a strip of orange peel from the syrup for decoration.