Line the springform pan (26 cm) on the bottom with baking paper.
Separate eggs. Egg white, 4 tablespoon. Beat cold water and a pinch of salt until stiff, while drizzling in the sugar. Beat in the egg yolks one by one.
Sieve the flour, pudding powder and baking powder on top, fold in. Brush into the form. Bake in a preheated oven at OH / UH 175 degrees for about 25 minutes. Make a test. Take out of the mold and let cool down.
Use the knife to mark a 2-3 cm wide edge on the cake base, hollow out the inside to a depth of approx. 1 cm. Finely crumble the biscuit pieces with your hands. Groats up to 2-3 tablespoon. Fill into the cake base.
Whip the cream and espresso powder until stiff, adding 1 tablespoon. Sprinkle in the sugar and vanilla sugar. Spread lightly on the cake like a dome. Splot the rest of the groats in the middle. Scatter the biscuit crumbs on the edge, dust with powdered sugar.