Sift the remaining flour, baking powder and a pinch of salt into a separate bowl. Add half into the batter and use a large metal spoon to gently fold it in, being careful not to knock out any air. Add the remaining flour mixture and gently fold in. The mixture should drop off the spoon easily – if not, add 1 tbsp of milk and gently fold again. Divide equally between the tins and bake for 20-25 minutes or until risen, golden and a skewer poked into the centres come out clean. Cool for 10 minutes in their tins, then turn out onto a wire rack to cool completely.