Preheat your oven to 180 C or 350 F
Butter and flour a 8 inch square pan and line the bottom with parchment paper (optional )
Prepare the ingredients - peel and mash up the bananas .Chop the pineapple as finely as possible. Toast the walnuts on a hot pan for few minutes and chop irregularly.
In a large bowl , whisk together the flour , sugar , salt , baking soda and cinnamon ( all dry ingredients )
Add the oil, curd and mashed banana and whisk.
Add in the chopped pineapple, coconut and walnuts and fold in or whisk until distributed.
Pour batter into pan and smoothen top
Bake for 35 to 45 minutes until the cake is coming away from sides of pan and a toothpick inserted in centre comes out clean
Cool in pan for 10 minutes, Unmould carefully and cool completely on a wire rack