In a large mixing bowl, mash the bananas to your desired smoothness. I prefer the puree to be slightly chunky and not too smooth.
Finely chop the palm sugar.
Add the palm sugar to the banana puree, and the sugar. Stir to thoroughly combine.
Add the flour, a quarter cup at a time, and stir combine.
Add the rice flour, and stir to combine.
Transfer the mixture to a medium-sized skillet over medium heat and cook, stirring constantly, until thickened, 3 to 5 minutes.
Prepare the banana leaf wrappers. Cut the banana leaves into 7- to 8-inch wide pieces. Soften the leaves by placing them over an open flame of your gas stove for a few seconds, until wilted.
Make the filling. In a medium-sized bowl, add the grated coconut. Sprinkle with the salt and stir to combine.
Assemble the lepat. Working with one piece of banana leaf wrapper at a time, add two tablespoons of the banana mixture.
Add a teaspoon of the coconut filling in the center of the banana mixture, distributing evenly along the length.
Fold along the long edge until the ends meet, and fold once as if folding the top of a brown paper bag. Then, fold the edge once more, and flatten.
Fold and tuck both ends.
Place in a steamer, folded side down. Repeat with the remaining filling and wrappers.
Cover and steam for 15 to 20 minutes.
The lepat will be softer fresh out of the steamer, but will set and become firmer when cool.
Enjoy!