Ma Lai Go (Cantonese Steamed Sponge Cake)

In a small saucepan, combine dark brown sugar and 50 grams of water. Heat gently over low heat, stirring until the dark brown sugar is fully dissolved and the mixture forms a syrup. Let it cool completely.

In a large mixing bowl, whisk the eggs and caster sugar together until light and frothy.

In a separate bowl, sift together the self-raising flour and custard powder.