Place the flour, baking powder, salt and sugar in a bowl and whisk to mix well. Make a slight well in the middle then add the melted butter, egg and around three quarters of the milk.
Whisk the mixture to form a smooth batter. Gradually add more of the milk until you get a thick but flowing consistency - it will be thicker than a crepe batter but still flowing. You might need all the milk or just a little less.
Warm a griddle, crepe pan or medium-large skillet/frying pan over a medium heat. Lightly brush the top with melted butter or oil, unless it is a non-stick surface that doesn't need fat added.
Add heaped spoonfuls of the mixture, around four at a time, and gently shape a little to be roughly circular. They should be a little heaped so don't spread much. Leave the batter to cook for a couple minutes until bubbles form and start to pop on the top.
Turn the pancakes over - the cooked side should be gently golden - and cook for around 30 seconds to a minute on the second side, until the underside is gently brown as well. Remove the pancakes from the pan and keep warm under a clean kitchen towel/tea towel. Repeat cooking the rest of the batter in batches.