Preheat oven to 350 degrees
Grease a 9x13in pan
Mix the melted butter and sugar in a large bowl with a mixer
Add the eggs, one at a time, mixing well between each
Add the vanilla, mix well again
Fold in the rice flour and baking powder (the mixture will look pretty dry at this stage)
Add in coconut milk and evaporated milk then mix well with mixer until the batter is nice and smooth
Pour the mixture in the pan
Top with desiccated coconut if desired, then bake for an hour
Allow to cool to room temperature. Cut into pieces and serve
