Let raspberries thaw at room temperature. Cut the pineapple into small pieces. Mix yoghurt, mascarpone, 50 g sugar, vanillin sugar and lemon juice with the whisk of the hand mixer.
Put 8 pineapple pieces aside for decorating. Stir the rest of the pineapple into the cream. Whip the cream until stiff. Carefully fold into the cream in portions. Puree raspberries and remaining sugar.
Pour cream into four dessert glasses. Serve with the pineapple pieces and some raspberry sauce. Serve decorated with mint and baby pineapple as desired. Serve with the rest of the raspberry sauce separately.