Add lemon juice in milk and keep it aside for 10 mins.take bananas mash it.now add vanilla extract, butter and lemon milk mixture. Mix all properly and keep it aside

In a separate bowl take flour,cocoa powder,casting sugar,baking powder,baking soda& mix it well

Now add this dry ingredients in to the wet ingredients in two batches using cut fold method and mix it thoroughly

Once mixed transfer the batter into the mould and bake it in pre heated oven at 180⁰ c for 60 mins

Once cake has been cooled remove it from mould garnish wit some chocolate sauce