Set oven to 170°C with shelf in middle
Break 4 eggs into a bowl and weigh (about 200-210g)
Add same weight of butter, caster sugar and flour to eggs, keeping flour on top
Add 2 teaspoons of baking powder on top of flour
Cover baking powder with 3 tablespoons of hand hot water and let it fizz for a couple of seconds
Use a mixer to mix everything together for a few minutes until very smooth and creamy
Divide between two 8 inch tins and bake in centre of oven at 170°C until golden brown (about 20-25 minutes)
Check after 20 minutes with a sharp knife which should come out clean
