Combine the butter, evaporated milk, sugar and vanilla essence in a saucepan.

Cook on low flame till the butter is melted and sugar is well combined. Keep aside to cool.

Add the lightly beaten egg into the slightly cooled mixture and whisk till well combined.

Sift all the dry ingredients and add it to the egg mixture and whisk well till combined. The batter will neither be thick nor watery.

Heat your steamer for around 10 minutes.

Grease and dust your 8 inch cake pan well. Pour the cake batter into the pan and lower it down to your steamer.

Close the lid and cook on meduim-low flame for 30-40 minutes or till a cake tester/ toothpick comes out clean.

Leave it to cool for sometime in the pan, and then flip onto a cooling rack to cool completely. Slice and serve or have it with ganache.