Wash and stone the cherries. Add sugar and liqueur and let marinate for about 1 hour. Cream egg yolk and icing sugar with the whisk of the hand mixer. Add yoghurt and stir in. Whip cream and vanilla sugar until stiff and fold into the yoghurt mixture.
Drain the cherries and carefully fold into the yoghurt mass. Place paper cups in the recesses of a muffin baking tray and spread the yoghurt cream mixture in them. Leave in the freezer for 4-5 hours. Results in 12 muffins
(without waiting)