Start this recipe by sifting together the flour and baking powder into a large bowl. Add in the sugar and butter and rub gently with your fingertips until the mixture resembles breadcrumbs. Add in the sultanas and ¾ of the milk and mix to a soft dough using a large spoon. Add in the remaining milk if necessary, but do not overwork the dough as the scones will become tough. Leave the dough to rest for 10 minutes, before rolling out on a floured surface to about 1 inch thick. Using a 6cm cutter cut out rounds and place on baking sheets. Brush the tops with the beaten egg, and bake in the oven at 220`c for about 10-12 minutes. Remove from the oven and transfer to a wire rack. Serve the scones either warm or cold with butter.