Beat eggs, sugar and water until creamy. Sift flour over the mixture and fold in. Cover the bottom of the springform pan with parchment paper and spread the batter into the pan. Bake in a heated oven at 180 degrees for about 20 minutes. Remove from the pan, turn out onto a wire rack, remove the paper and cool.
Remove the pulp from the melons. Grind 400 grams of it (per cake), put the rest aside. Stir the puree, yogurt and sugar. Stir in dissolved gelatine. Place in refrigerator until semi-solid.
Place sponge cake on a cake plate. Place a strip of parchment paper about 10 cm wide and a springform rim around the sponge. Brush the fruit mixture. Cool and set well.
Cover the cake with icing. Cut out balls from remaining melon pulp and pile them in center of cake. Spread a thin layer of whipped cream on the edge of the cake and press the meringue crumbs smooth.
We wish you good luck!