Beat butter, milk, eggs and sugar together until sugar has dissolved.
Sift flour, salt and baking powder together.
Add milk mixture to flour and mix to a smooth batter.
Allow to stand for 15 minutes.
Drop spoonfuls of batter onto a hot, greased griddle or frying pan.
When bubbles rise to the surface of the crumpets, turn them over and allow to cook on the other side.
Repeat with remaining batter and serve with sliced banana and yoghurt.