Preheat oven to 175 degrees. Separate the eggs and beat the egg whites until stiff. Beat the egg yolks with sugar and 1 packet of vanilla sugar until creamy. Pile the egg whites on top. Sieve cornstarch, flour, baking powder and 1 tablespoon cocoa over the top. Mix everything together. Bake the mixture on a baking sheet lined with baking paper on the middle rail for approx. 15 minutes. Turn over, after cooling, divide into 3 rectangles. Place a square baking frame around one of the three shelves.
Mix the espresso with 6 tablespoon Bailey`s and sprinkle all 3 bases with it. Mix the mascarpone, 2 sachets of vanilla sugar and 4 tablespoons of Bailey`s until smooth.
Dissolve the cream stiffener in the cream, beat until stiff and fold into the mascarpone. Spread 1/3 of the cream on each base. Place all bases on top of each other and cool the cake for at least 60 minutes.
Cut the well-chilled cake into 10 slices. Strain the remaining 2 - 3 tablespoons of cocoa powder through a sieve and dust. Garnish with mocha beans.