Using the bamix® multi-purpose-blade, mix the mascarpone with the plain yoghurt, sugar, lemon juice and, if desired, Himbeergeist. Whip the cream using the bamix® beater and fold it into the mascarpone mixture. Cut the sponge fingers into small pieces. Wash and dry the raspberries. Layer the sponge fingers, cream and raspberries in glasses, starting with the sponge fingers. Store in a cool place overnight.