Wash, drain and clean the strawberries. Cut 300 g strawberries into small cubes. Separate eggs. Beat egg whites, vanilla sugar and 100 g sugar with the whisks of the hand mixer until stiff.
Stir in the egg yolks. Mix starch, flour and cocoa, sieve and carefully fold in. Fold in strawberries. Line the bottom of a baking tray (approx. 34 x 39 cm) with baking paper. Spread sponge mixture on top.
Bake in the preheated oven (electric cooker: 175 °C/ convection oven: 150 °C/ gas: see manufacturer) for approx. 12-15 minutes. Remove from the oven and let cool on a cake rack.
Soak 6 sheets of gelatine in cold water. Mix quark, coconut milk, coconut flakes and 125 g sugar. Whip the cream with the whisks of the hand mixer until stiff. Squeeze the gelatine, dissolve and stir in 3 tbsp. of the quark mixture, then stir into the remaining quark mixture.
Carefully fold in the cream. Spread the cream on the sponge cake base and refrigerate for at least 1 1/2 hours.
Cut the remaining strawberries into small cubes. Soak 2 sheets of gelatine in cold water. Cut mangoes from the stone. Peel the flesh, dice something for decoration, puree the rest of the flesh.
Squeeze the gelatine, dissolve and mix with 3 tbsp. mango puree, then stir into the remaining mango puree. Spread over the cream and smooth it down. Put in a cool place for at least 1 hour. Cut into approx. 5.5 x 11 cm slices and decorate with strawberry and mango cubes.