Wash the rice under cold water. Rinse it until the water becomes pretty clear. Soak the rice in water and set aside.
In a double boiler, bring the water to a boil. In the pot or bowl above the water, add in 3½ coconut milk. Set aside the reserved 1/2 cup of coconut milk. Cook the coconut milk for about 15 minutes while constantly stirring.
Add in 1 cup brown sugar. Set aside the reserved 1/2 cup of brown sugar. Let it cook for another 15 minutes while stirring constantly.
Add in the rice and constantly stir it until it has thickened and looks like rice pudding.
Wilt the banana leaves over a flame or heat until the leaves turned into a mustard green color. Preheat the oven to 350°F. Line a 4x4 baking pan with the wilted banana leaves.
Pour the rice pudding into the baking pan, top it off with the reserved brown sugar and coconut milk, and pop it into the oven.
Let it bake for 15 minutes then lower the temperature to 300°F and let it bake for 30 minutes.
Cool to room temperature before cutting it into square pieces. Serve and enjoy!