For the chocolate crunch, chop the chocolate and melt in a hot water bath. Stir the cornflakes into the chocolate. Place the mixture in heaps on baking paper using two teaspoons. Leave to set in a cool place for about 15 minutes.
For the raspberries berries selected. Stir jam until smooth. Mix raspberries and jam carefully.
Whip until stiff for the cream. Cream the sour cream, vanilla sugar and sugar. Fold in the cream.
Approx. 2⁄3 of the chocolate crisp in a large dessert bowl. Add the raspberry mixture, except for about 3 tablespoons. Spread the sour cream on top. Coarsely crumble the remaining chocolate crunchies. Sprinkle over the trifle before serving. Serve with the remaining raspberries.