Soak gelatine in cold water. Clean, wash, halve and stone the cherries. Sort raspberries. Heat 125 ml Prosecco and vanillin sugar. Let the cherries steep in it for a short time.
Pour into a mixing bowl, let cool lukewarm. Squeeze the gelatine and dissolve in it. Stir in another 250 ml Prosecco and raspberries. Pour into 4 cold rinsed, tall dessert glasses, chill for about 1 hour. Coarsely crush the lady fingers and spread on the jellies. Sprinkle each with 1 tablespoon of Prosecco. For the sauce, whisk egg yolk, sugar and 125 ml Prosecco. Whip over a hot (!! not boiling!!!) water bath until thick and frothy.
Sprinkle each with 1 tablespoon of Prosecco. For the sauce, whisk egg yolk, sugar and 125 ml Prosecco. Whip over a hot (!! not boiling!!!) water bath until thick and frothy. Beat over a cold water bath for about 3 minutes more. Spread immediately over the dessert glasses and serve