Stir the butter with the sugar vigorously until the substance is foamy.  Add the egg and keep mixing while adding the rest of the ingredients until the dough is ready.  It should be tender but of a firm consistency.  The biscuits should be placed onto a non-greased baking tin and should be ba(c)ked in the pre-heated over for about 15-20 minutes at a temperature of 170-190 degrees C.