Line a baking tray (approx. 35 x 40 cm) with baking paper. Separate the eggs. Beat egg white, 4 tbsp. cold water and salt until stiff. While continuing to beat, add 150 g sugar, vanillin sugar and espresso powder and continue beating until everything is completely dissolved. Mix flour, starch and baking powder, sieve and fold in
Spread on the baking tray. Bake in the preheated oven (electric cooker: 200 °C/recirculating air: 175 °C/ gas: level 3) for 10-12 minutes. Turn the sponge cake onto a tea towel sprinkled with sugar. Remove baking paper and let the sponge cake cool down
Knead 50 g icing sugar and marzipan. Roll out to a rectangle (approx. 18 x 33 cm) on a little icing sugar. Halve the sponge cake to 2 smaller plates, sprinkle with liqueur
Spread 1 plate with half of the jam and cover with marzipan. Spread the rest of the jam on top. Place 2nd plate on top. Weigh down with a tray. Let rest for 1-2 hours
Straighten the edges of the biscuit plate. Cut the plate into about 50 cubes (approx. 3 x 3 cm). Roughly chop dark chocolate and melt in a hot water bath. Cover the cake cubes with it and let them dry
Chop white couverture and melt in a hot water bath. Pour into a freezer bag, cut off a small corner. Decorate the petits fours with white couverture strips, chocolate beans, hearts and pistachios. Allow to dry completely