Separate eggs. Beat the egg whites and 3 tbsp. cold water until stiff, adding 100 g sugar. Stir in egg yolks. Mix flour, starch and baking powder and fold into the egg mixture. Line baking tray with baking paper. Spread the mixture evenly over the baking tray. Bake in the preheated oven (electric cooker: 200 °C/ convection oven: 175 °C/ gas: level 3) for 10-12 minutes. Sprinkle 1 tablespoon of sugar on the tea towel.
Turn the cake over and remove the paper. Wash 1 orange hot, rub dry and thinly grate the peel. Peel all oranges so that the white skin is completely removed. Remove the fillets with a sharp knife between the parting skins. Squeeze the juice out of the parting skins (yields approx. 175 ml juice). Mix 6 tablespoons of sugar and cream firming agent. Whip the cream with the whisk of the hand mixer until stiff. Trickle in the sugar mixture. Cut the sponge cake base in half crosswise. Place a cake frame around one base. Cover with orange filets. Mix 2/3 of the cream with orange zest and 4 tbsp. orange juice. Spread the cream mixture on the fillets and smooth it down. Place 2nd base on top. Pour the remaining cream into a piping bag with a perforated spout. Spray the cream in strips on the upper base.
Place a cake frame around one base. Cover with orange filets. Mix 2/3 of the cream with orange zest and 4 tbsp. orange juice. Spread the cream mixture on the fillets and smooth it down. Place 2nd base on top. Pour the remaining cream into a piping bag with a perforated spout. Spray the cream in strips on the upper base. Chill the cake for at least 1 hour. Mix the cake glaze and 1 tbsp. sugar in a small saucepan. Measure out 100 ml orange juice and gradually pour into the cake glaze. Stir with a wooden spoon until smooth. Boil up while stirring. Pour the icing into a disposable piping bag and let it cool down briefly. Cut off the top and decorate the surface of the cake with fine strips. Wait until the icing has set, loosen the baking frame and cut the cake into pieces
Chill the cake for at least 1 hour. Mix the cake glaze and 1 tbsp. sugar in a small saucepan. Measure out 100 ml orange juice and gradually pour into the cake glaze. Stir with a wooden spoon until smooth. Boil up while stirring. Pour the icing into a disposable piping bag and let it cool down briefly. Cut off the top and decorate the surface of the cake with fine strips. Wait until the icing has set, loosen the baking frame and cut the cake into pieces
Waiting time approx. 1 hour