Combine rice flour, yeast, salt, sugar and coconut milk in a mixing bowl. Stir into a smooth batter then cover with a clean tea towel. Leave mixture to rest for 40-45 minutes or until doubled in bulk.
Heat a miniature kuali or pan over medium high heat. Lightly grease the kuali with a piece of oiled cloth. Pour a ladle of batter into the kuali. Swirl the batter to coat the kuali evenly, then cover with a lid. Allow to cook for 2-3 minutes over a gentle low heat.
Once the edges are light golden brown, use a spatula to scrape around under the apom. Lift it out of the pan and continue with the rest of the batter.