Put the self-raising flour and baking powder into a large mixing bowl.
Take your butter, cut into small cubes and add them to the mixing bowl.
Rub in lightly and quickly with your fingertips until the mixture looks like fine breadcrumbs.
Then, add the 2 tsp of sugar and 1/2 cup of sultanas.
Beat your egg in a separate bowl, and add 150ml of the milk and whisk together. Begin slowly adding the milk mixture to the large bowl of ingredients. Leave some of the egg/milk mixture for brushing on the scones later.
Together with your hands, mix the dough. Make sure it is not too sticky, adding a bit more milk if needed to mop up any dry bits of mixture in the bottom of the bowl.
Turn the dough out onto a lightly floured work surface, lightly knead just a few times only until gathered together, then gently roll and pat out to form a rectangle about 2cm deep.
Cut out as many rounds as possible from the first rolling with a 6cm cutter (a plain cutter is easier to use than a fluted one) and lay them on parchment/baking sheet, spaced slightly apart.
Gather the trimmings, then roll and cut out again. Repeat until you have around 6/8 scones.
Brush the tops of the scones with the reserved egg/milk mixture.
Put into the hot oven and bake for about 10 minutes, or until risen and golden.
Remove and cool on a wire rack.
Serve with homemade jam and clotted cream or salted butter.