Dice the nougat. Bring the cream to boil and melt the nougat in the hot cream. Let the nougat cream cool down and put it in a cool place overnight
Chop the chocolate and melt over a hot water bath. Separate eggs. Beat the egg whites and 3 tbsp. cold water until stiff, adding sugar. Fold the egg yolks into the beaten egg white. Mix starch, flour and baking powder. Sift the flour mixture over the mixture and fold in. Fill half of the mixture into a piping bag with a perforated nozzle (approx. 1 cm Ø)
Spray diagonally onto a baking tray lined with baking paper diagonally light-coloured sponge cake strips at a distance of about 1 cm. Fold liquid chocolate under the remaining sponge cake mixture and fill into a piping bag with punched spout (approx. 1 cm Ø). Spray dark sponge cake in strips between the light sponge cake
Bake the sponge cake in a preheated oven (electric cooker: 200 °C/ convection oven: 175 °C/ gas: level 3) for approx. 8 minutes. Remove and turn out onto a tea towel sprinkled with sugar. Remove the baking paper. Roll up the sponge cake with the tea towel and let it cool down
Whip the nougat cream with the whisk of the hand mixer for approx. 3 minutes (until the mixture is stiff), allowing the cream setting agent to trickle in. Unroll the sponge cake and spread with the cream, leaving about 1 cm free on the upper long side. Roll up the sponge cake from the lower long side and refrigerate for 1 hour. Sprinkle the roulade with cocoa, cut open and arrange on a plate
waiting time approx. 13 hours