These are also known as Scotch Pancakes, especially in the north. They must be cooked as soon as possible after mixing, as the acid in the buttermilk starts to react with the baking soda at once. For that reason the griddle or pan should be heated before combining the ingredients.
Sift the dry ingredients into a bowl. Make a well in the middle with a wooden spoon and add the egg. Break the yolk and pour in the buttermilk, mixing quickly to a thick batter. Do not beat, as this would develop the gluten in the flour and prevent the pancakes from rising. Fry in large dollops on a lightly-greased, hot griddle or heavy frying-pan. Drop scones are best served hot for tea, thickly spread with melting butter and syrup or jam.
Here is an easy way to make thin pancakes:
Put all the ingredients in a blender and blend for about 30 seconds. The batter should then be allowed to stand for 30 minutes in a cool place. Heat a small pan over a medium heat. Grease with a little butter and wipe out with kitchen paper. Fry about 2 tbsp of batter at a time, swirling to cover the base of the pan. Keep them thin and there will be no need to turn. Serve rolled up with sugar.