Soak the gelatine in water, beat the egg white until stiff. Mix the mascarpone with the powdered sugar and vanilla sugar.
Heat the milk, remove it from the stove and dissolve the cappuccino powder and the squeezed gelatine in it. Cool and add to the mascarpone. Stir in the egg whites.
Whip the cream until stiff and fold in as well. Let it set in the refrigerator.
Before serving, whip again briefly and sprinkle with cocoa.