How To Make Special Cotton Sponge Cake

How To Make Special Cotton Sponge Cake
    60g butter, melted
    80g flour, sifted
    80ml full cream milk
    1 whole egg
    5 egg yolks
    5 egg whites
    120g caster sugar
    Line a baking pan and set aside.
    Melt butter ( you can use a microwave) and pour it into a mixing bowl.
    Add sifted flour and use a spatula to mix the flour and butter until well blended.
    Add milk and continue to mix.
    Add egg yolks, one by one, mixing as you go along, followed by the whole egg. Set aside.
    Using a handheld mixer, beat egg whites until foamy and add sugar.
    Continue to beat until stiff peaks.
    Pour the egg yolk mixture into the egg whites and fold to mix until you do not see any streaks.
    Pour batter into the lined pan and bake at 150°C for 1 hour and 50  minutes on the middle rack until a skewer inserted into the center of  the cake comes out clean.
    Remove the cake from the oven immediately and drop it from a height (about 12 inches ) onto your tabletop.
    Unmold the cake and leave it to cool completely before serving.