Into a blender, add the whole eggs, the unsalted butter or margarine, the vanilla essence and the sugar, let it all blend very well for 5 minutes.
Then add the tapioca starch and the milk, blend again for another 5 minutes.
Finally, turn off the blender and add the baking powder, use the ‘pulse’ function of the blender to mix gently.
Now grease a medium baking tray with unsalted margarine, use a sheet of paper towel to spread it.
Evenly spread some tapioca starch all over the baking tray.
Then pour the whole cake batter into the tray.
Bake in a preheated oven at 180°C (356°F) for 40 minutes, baking time may vary depending on the power of your oven.
Serve.