• 200 g (7 oz) butter
• 250 g (9 oz) black glutinous rice flour
• 6 large eggs
• 250 g (generous 1 cup) caster sugar
• ½ teaspoon salt
• 1 teaspoon baking powder
• 2 tablespoons sweetened condensed milk
• ½ teaspoon vanilla extract

You’ll need a cake tin and a steaming pan or basket large enough to hold it. I use a 22 cm (8½ inch) bundt tin, which fits neatly into my steamer.

Melt the butter and use a little to grease the inside of the cake tin well. Dust with just a little of black flour to help stop the cake sticking. Start the water boiling underneath the steamer so it is ready for the cake.

In a large bowl, whisk together the eggs, sugar and salt to get a frothy mixture with the sugar dissolved. Stir in the black glutinous rice flour and baking powder.

Stirring as you go, gradually add the condensed milk, the vanilla extract and finally the melted butter. Keep stirring until the mixture is smooth and velvety.

Pour into the cake tin and sit in the steaming basket. Wrap the lid with a clean tea towel - this will stop water dripping onto the cake and create a tight seal. Steam over a medium-low heat (making sure there is always water in the pan). How long it will take depends on the size and shape of your pan - Aisah’s takes 25 minutes, mine closer to 40. Check every 5 minutes or so towards the end of the cooking time. The top should be gently springy with not too much wobble below, then poke in a skewer to check the middle has a delicate crumb rather than raw batter.

Remove from the steamer and leave to cool for 10 minutes in the tin before turning out onto a rack to cool. Serve with strawberries perhaps, or for a real Indonesian touch, grated mild cheddar cheese.