Grease and line with baking paper two 20cm (8 inch) round springform baking pans.
In a bowl add plain flour, baking powder and salt and mix together.
In a separate bowl mash bananas with 1 tsp lemon juice and stir to combine.
In a large bowl add butter, 2 tbsp vegetable oil, white sugar & brown sugar. Using electric beaters, mix until pale & fluffy.
Add remaining 2 tbsp vegetable oil & eggs and mix until combined. Add eggs one at a time and mix through after each addition. Don’t over beat.
Add vanilla extract and mashed bananas and stir to mix through.
With beaters on low speed, add flour and buttermilk in alternating batches. Mix until just combined.
Divide mixture evenly between the 2 baking pans and place in oven. Cook for about 50 minutes or until a skewer inserted into the centre of the cake comes out clean.
Remove from oven and allow to cool in baking pans for about 10 minutes before turning out onto wire racks to cool completely.
Vanilla Cream Cheese Icing
Add thickened cream to a bowl and beat with an electric mixer until stiff peaks form.
In a separate bowl, add cream cheese & butter and beat until smooth and fluffy.
Add icing sugar and vanilla extract and beat until fully combined.
Add the thickened cream mixture and fold through until combined.
Cake Assembly
Place one cake onto a plate and spread with vanilla cream cheese mixture.
Place second cake on top and spread cream cheese mixture over the top and sides of the cake.
Place cake in refrigerator to all icing to firm before serving. Store in refrigerator.