Preheat oven to 220°C. Line a baking sheet with baking paper if needed.
Sift flour, cream of tartar, baking soda & salt into a bowl. Rub in the butter until the mixture resembles fine breadcrumbs.
Stir in the sugar & enough milk to mix to a soft dough
Turn out onto a floured surface, knead lightly & roll out to a 1 1/2cm thickness.
Cut into squares or rounds & place on the baking sheet or tray.
Brush with the 2 tablespoons of milk to glaze.
Bake at 220°C for 10mins & then cool on a wire rack .
Serve cut in half, spread with butter & jam and whipped cream for a classic afternoon tea.
Variation: add 70g of chopped dates to the mixture before kneading for date scones.