Soak the rice for at least 4 hours or overnight in water
Drain the water you use to soak the sticky rice. Place the sticky rice in a tray (I use 7-inch round tray). Pour in the coconut milk and salt and stir to mix. Place this in a steamer and steam on high heat for about 25-30 minutes or until cooked through and soft. Remove from the steamer. Refill water in the steamer if necessary and get it ready to steam the cake again later. Wrap the lid of the steamer with a cloth to prevent water dripping back on the cake, which will make the surface of the cake not smooth
Cooking sticky rice with Instant Pot pressure cooker:
No need to soak the rice. Place all the ingredients for the rice (bottom layer) in a pan that is at least 3-inch height and can fit in your instant pot. Stir to mix and make sure the rice is covered by liquid. Close the lid. Turn the steam release valve to "sealing". Press "pressure cooker" and make sure it's on "high pressure". Set timer to 15 minutes. Wait 10 minutes and then fully release pressure
Pressing the rice cake:
Grab an 8x8-inch square tray or 9-inch round tray and brush with some oil on the bottoms and all sides. Cut a parchment paper to line the bottom of the pan. This will make your life easier when you try to remove cake from the pan. Transfer the sticky rice to the tray. Cover with a piece of parchment paper and really use your palms to pack the rice down so your cake won't fall apart when you cut it
Preparing the top layer:
Place the eggs and sugar in a large mixing bowl. Use a balloon whisk and whisk until the sugar melted. I find it easier when you do it this way first. Add the coconut milk, pandan juice and stir again to mix. Add in all-purpose flour and tapioca flour. Stir until the mixture is smooth.
Strain this mixture again into a large saucepan to catch any lumps. Cook this over low heat and stir until the mixture can coat the back of the spoon. May take about 15-20 minutes. Don't be tempted to crank the heat up as the custard will be lumpy later. Remove from the heat and continue stirring few more times. If the custard happens to be lumpy, you can use an immersion blender or blender to smooth it. This will ensure you have a smooth top
Transfer the mixture to a cup with a spout. I find it easier to pour. Pour this mixture gently to avoid any bubbles over the pressed rice cake. Place two long chopsticks on top but more at the sides (to prevent water condensation from collecting on the chopsticks dripping back to the cake, it happened to me before).
Steaming the cake:
Place the lid (wrapped with cloth) on top of the chopsticks, this creates some gap to allow some steam to escape. Steam on medium heat for the next 30-45 minutes or until the top layer is no longer "jiggly". Carefully remove the lid and chopsticks and remove the cake from the steamer and let it cool down completely before cutting, about 4 hours or so
Loosen the edge with an oiled knife or plastic knife and then gently transfer the kueh out from the pan and cut to desired size
Kuih Seri Muka / Kueh Salat (with smooth surface) https://whattocooktoday.com/seri-muka-kuih-salat.html