In a mixing bowl, combine the glutinous rice flour and salt. Gradually add in water while mixing until the dough is smooth and well-combined.
In a saucepan, combine the brown sugar and 1/2 cup of water. Cook over medium heat until the sugar is dissolved and the mixture is thick and syrupy.
Add the syrup to the mixing bowl and stir until well combined. Add in the vegetable oil and mix well.
Cut the banana leaves into 8-inch squares and dip each leaf into boiling water for a few seconds to soften them.
Place about 2 tablespoons of the rice mixture onto the center of a banana leaf square. Fold the sides of the leaf up and over the filling to create a rectangular package.
Tie the package with kitchen twine to secure it closed.
Repeat with the remaining rice mixture and banana leaves.
Place the packages in a steamer basket and steam for 20-25 minutes.
Once cooked, remove the packages from the steamer and allow them to cool before serving.
