Beat together the sugar, egg yolks and water using the whisk on a hand mixer for approx. 5 mins. until the mixture is light and fluffy. Beat the egg whites with the salt until stiff, add the sugar, continue beating until the egg whites turn glossy. Mix the flour and chocolate powder, layer with the egg whites on top of the mixture, carefully fold in using a rubber spatula, transfer to the prepared tin.
Approx. 30 mins. in the lower half of an oven preheated to 180°C. Remove from the oven, allow to cool slightly, remove the tin frame, leave the sponge to cool on a cooling rack. Cut twice through the sponge, place the base on a cake plate.
Combine the icing sugar, water and lemon juice, drizzle 4 tbsp of the lemon icing over the sponge base. Spread 1/3 of the whipped cream and half of the cherries over the sponge base. Place the second sponge on top, drizzle with 4 tbsp of the lemon icing. Top with half of the whipped cream and the remainder of the cherries, place the third sponge on top (cut side up), press down gently, drizzle with the remainder of the lemon icing. Spread the remainder of the whipped cream over the top of the cake, cover and chill for approx. 1 hr.
Top the cake with the cherries and chocolate shavings.