Before making the batter, make sure all of your ingredients are at room temperature.
Preheat the oven to 180°C/356°F (without fan).
Place a metal baking tray in the middle of the oven to preheat.
Generously grease a 12-hole muffin tray or similar with the 35 g of melted butter (you may not need all of it).
In a large mixing bowl, preferably with a spout, whisk together the sugar and eggs until it is light and pale.
Whisk in the milk, vanilla and melted butter.
Finally, add the glutinous rice flour and salt.
Whisk until you have a smooth batter.
Carefully pour the batter into the prepared moulds, filling each mould ¾ full. The batter will rise and puff up during baking, so it is important to not over-fill the moulds.
Place the filled moulds onto the preheated baking tray in the oven.
Bake for 30-35 minutes, or until the cakes are nice and golden. The cakes will generally be flat on top, but some cakes may rise and remain puffed up.
Serve the cakes hot or warm.
Leftovers can be stored in the fridge and reheated in the air fryer.