2 cups flour1 ½ teaspoon baking powder1 teaspoon salt170g butter, cut into small cubes and melted1 cup brown sugar½ cup icing sugar1 teaspoon vanilla essence1 egg + 1 egg yolk200g milk chocolate cut into chunks1. Place melted butter into a bowl. Add brown sugar and icing sugar and beat well. Then add vanilla essence and mix.2. All the mixture to cool down.3. In another mixing bowl, add flour, baking powder and salt. Lightly mix together.4. Add egg and egg yolk to the cooled butter mixture and beat.5. Pour the butter mixture into the flour mix and stir well until combined. The dough will be fairly stiff at this stage.6. Add the chocolate chunks and mix through.7. Roll into balls and place in a baking tray. Leave plenty of space between the balls as the cookie spreads quite a bit.8. Bake for 15mins at 160 deg or until golden. .