Halve the lady fingers and sprinkle with 4 tablespoons of cherry liqueur. Mix the remaining liqueur with the cranberries. Mix quark, sugar, milk and 1 packet of vanilla sugar. Whip the sour cream and remaining vanilla sugar until creamy and fold into the quark mixture.
Spread some cream in 4 glasses and place the lady fingers on the edges of the glasses. Layer the remaining cream in the glasses alternating with the cranberries. Use a fork to draw a loop through the cream and keep cool until serving. Serve decorated with melissa