Using the Kenwood Titanium XL Mixer with the balloon whisk attachment on high speed, mix eggs, vegetable oil and brown sugar for 5 minutes. Add vanilla extract, evaporated milk and custard powder. Mix well again for 1 minute.

Sift cake flour, salt and baking powder. Gently fold sifted ingredients into egg mixture until well incorporated. Try to break up large lumps, but do not overwork the batter. Set aside for 30 minutes.

Gently stir batter again in a folding motion, just enough to mix batter uniformly. You should be able to see that the batter has thickened. Pour batter into bamboo steamer basket lined with parchment paper. Let it sit for another 10 minutes.

Place steamer basket onto steamer at medium-high heat for 30 minutes until fully cooked. Set aside to cool before slicing.
Tip: To check if cake is completely cooked through, insert a toothpick into the centre of the cake. It is cooked when the toothpick comes out clean without any batter.