Combine the warm milk and lemon juice in a bowl, mix well and keep aside for few minutes.
Combine the plain flour, cocoa powder, sugar, baking powder and baking soda in a deep bowl and mix well. Keep aside.
Combine the bananas, melted butter, vanilla essence and milk-lemon juice mixture and mix well using a spatula. Keep aside.
add the plain flour-cocoa powder mixture to the banana mixture and fold it using a spatula.Add the chocolate and walnuts and mix well.
Pour the batter into a greased cake loaf tin, pat the tin lightly so that the batter spreads evenly.
Sprinkle the chocolate chips evenly over it.
Bake in a pre-heated oven at 180°c for 20to 25 minutes.
Cool it, loosen the edges using a knife and demould it by inverting the tin over a rack and tap gently to unmould the loaf.
Cut into thick slices and serve immediately or store in an air-tight container. Use as required
