225g (8oz) flour
125g (4oz) butter
25g (1oz) icing sugar
1 egg yolk
1 t baking powder
Water, cold
Sift flour, sugar, and salt, rub in butter and baking powder, and mix to a very stiff dough with egg yolk and a little water. Roll out lightly and handle as little as possible. Bake at 200C for about 10 to 15 minutes.
Source: Edmonds Cook Book, page 60