Take a pan and add remaining milk in it. Bring the milk to a boil over low/medium flame. After few seconds, add the custard powder mixture in the pan and stir well. Once the mixture starts to thicken, add the chopped bananas. Once done, remove the pan from flame and add vanilla essence, nuts and raisins in it.

Give it a nice stir and keep it in the fridge for 2 hours. Transfer the banana custard in serving bowls and garnish with chocolate shavings. Serve chilled to your family and friends. You can also garnish the custard with whipped cream for an extra sweet flavour.