Preheat the oven to 170°C/325°F/Gas Mark 5.
Line and grease 3 20cm cake tins.
Place the sugar, eggs, oil, banana and peaches in a bowl and whisk with an electric mixer.
Add the cinnamon, flour, bicarbonate of soda slowly and mix until all the ingredients are incorporated.
Add the walnuts followed by the yogurt.
Pour the mixture evenly into the prepared tins and bake in the preheated oven for 20-25 minutes, until springy to touch. Or use a skewer, if it comes out clean then the cakes are done.
Turn the cakes out onto a wire rack to cool.
Prepare the icing. Soften the cream cheese by placing it in a bowl and beat until smooth, ideally with an electric mixer then add the icing sugar and beat again. When the mixture is completely smooth, add the yogurt.
When the cakes are cold spread half of the icing onto two of the cakes to make the bottom layers and finally sandwich the third cake on top.
Chill the cakes and continue to make the syrup. Cut each passion fruit in half and scoop out the flesh and seeds. Make sure you catch all the juice. In a small saucepan heat the passion fruit pulp with the sugar and allow the mixture to come to a rolling boil. Allow to cool slightly, the syrup should thicken as it cools. Take the cake from the refrigerator and pour over the syrup allowing it to drizzle down the sides of the cake.