Wash 5 stems of mint, shake dry and chop finely. Separate eggs. Beat the egg whites and 3 tablespoons of cold water with the whisk of the hand mixer until stiff, adding 75 g sugar, 1 packet of vanilla sugar and salt to finish. Add egg yolks one after the other, fold in. Add the mint at the end. Mix flour, starch and baking powder, sieve onto the egg yolks and fold in carefully. Line the bottom of a springform pan (26 cm Ø) with baking paper. Fill in sponge mixture and smooth it down. Bake in the preheated oven (electric cooker: 200 °C/ convection oven: 175 °C/ gas: see manufacturer) for about 15 minutes. Leave to cool in the mould on a cake rack for approx. 3 hours
Soak gelatine in cold water. Pour the pineapple into a sieve, drain and puree it with 1 packet of vanillin sugar, except for approx. 8 pieces. Whip 600 g cream with the whisks of the hand mixer until stiff. Squeeze the gelatine and melt it in a small pot. Stir in 4 tablespoons of puree, then stir back into the remaining puree. Fold the cream into the puree. Cut the sponge horizontally. Place a cake ring around the lower cake base, spread pineapple cream on top and smooth it down. Place the second cake layer on top, press lightly and chill for 5 hours
Wash remaining mint, shake dry. Pluck leaves from the stalks. Roll the leaves in approx. 3 tbsp. sugar and let them dry. Halve the remaining pineapple pieces. Whip 300 g cream until stiff and spread the cake with cream using a tablespoon. Decorate the cake with the pineapple pieces and sugared mint leaves
waiting time approx. 7 hours