Put 200 ml of cold water into a mixing bowl. Add the cream powder all at once and beat with the whisks of the hand mixer at highest speed for about 3 minutes until foamy. Cut open the aroma capsule (located in the package), press the liquid into the cream and stir in evenly together with the yoghurt. Whip cream and vanilla sugar until semi-stiff.
Fold the cream into strips under the lemon cream and distribute in 4 glasses. Keep in a cool place for at least 11/2 hours. Serve decorated with lemon balm. Serve with fine waffle biscuits