Whip up the eggs with the sugar until you reach the ribbon stage. This happens when you can make a drawing with the batter on top of the surface and it doesn't sink back in immediately.
Mix the flour, salt and baking powder. Add half to the batter through a sieve or colander and mix it in using folding motions. Repeat with the other half. Always be careful not to leave flour at the bottom of the bowl where it tends to sink.
Mix in the evaporated milk and vanilla essence using folding motions with a spatula.
Pour the batter into a 20x30cm/8x12in baking dish or pan bake in a preheated oven at 180°C/350℉ for 20-30min or until you can insert a stick at the centre and it comes out clean.