Prepare the Bananas: Peel the bananas and slice them into thin rounds. If you prefer a smoother texture, you can lightly mash them. Set the sliced bananas aside in a mixing bowl.
Make the Coconut Milk Mixture: In a separate bowl, combine the coconut milk, sugar, and salt. Stir until the sugar is fully dissolved. If using pandan leaves, tie them into a knot and add them to the mixture to infuse a pleasant fragrance. Remove the leaves before mixing with the bananas.
Combine the Ingredients: Add the coconut milk mixture to the sliced bananas. Stir gently to coat the bananas evenly. Then, add the tapioca starch or rice flour to the mixture and stir until well combined. The flour will help to thicken the dessert and give it a cohesive texture.
Steam the Cake: Pour the banana mixture into a heatproof dish or cake pan. Prepare a steamer or a pot with a steaming rack and bring the water to a boil. Place the dish with the banana mixture into the steamer and steam over medium heat for 30-40 minutes. Check halfway through to ensure the texture is firming up, and adjust the steaming time as necessary. The cake should firm up and have a soft, pudding-like consistency when done.
Serve and Garnish: Once the Banh Chuoi Hap is fully steamed, remove it from the steamer and allow it to cool slightly. You can serve it warm or refrigerate it for a few hours to enjoy chilled. Optionally, garnish with sesame seeds, grated coconut, or a drizzle of sweetened condensed milk.
