Use a 9" round spring form tin. Arrange sponge fingers on bottom of pan, ensuring to cut fingers to cover base. Set aside.
Beat cream cheese, sour cream, yoghurt,egg yolks 1/4 cup plus 2 tbsp of sugar until smooth. Combine gelatin and water in a small saucepan. Simmer until gelatin is completely dissolved, stir into cheese mixture.
Beat egg whites with remaining sugar until soft peaks form. Fold egg whites, raspberries and mango into cheese mixture. Spoon filling onto sponge fingers. Refrigerate for 2-3 hours or until set.
To garnish, arrange raspberries in centre in a mound. Peel and slice mango thinly and arrange in a fan pattern around raspberries. Whip cream until stiff. With a piping bag pipe 8-10 cream rosettes around edge of cheesecake. Top rosettes with a sprig of mint.
