Preheat oven 200 degree celcius

Mix butter with sugar until the coulour turns pale

Add the rest of the ingredients, then mix just until it blends enough

Transfer batter to a greased baking dish. Then add the white chocolate chips

Bake for 10 mins with 200 degree celcius just to make the surface crisp. Lower the temperature to 175 degree celcius and bake for another 15-20 minutes

Cool to room temperature then slice!