Cocoa Roulade Sponge

Heat the oven to 220°C (200°C in a fan oven), 425°F, gas 7 and line a baking tray with greaseproof paper.

Separate the eggs and place the yolks in a mixing bowl. Add the vanilla sugar and two thirds of the sugar and beat with an electric whisk until creamy.

Beat the egg whites and the lemon juice until stiff and gradually beat in the remaining sugar.

Fold the egg whites into the egg yolk mixture and sieve in the flour, cornflour and the cocoa powder. Carefully fold in the dry ingredients with a spatula.

Spread the cake mixture on the prepared baking tray and bake in the middle of the oven for 10-12 minutes.

Sprinkle a large tea towel with sugar and carefully tip the cake onto it from the baking tray. Spread the baking paper with cold water and carefully remove it from the base of the cake. Immediately roll up the cake using the towel and leave to cool.

To make the filling, soften the gelatine in cold water.

Mix together the quark, sugar and the lemon juice until smooth.

Wring out the gelatine and place in a pot with the liqueur. Heat until the gelatine has dissolved and then stir in 3-4 tbsp of the quark cream. Transfer to the remaining cream and mix well. Fold in the whipped cream.