The night before - In a large bowl, whisk together the sourdough starter, milk, flour, and maple syrup until combined.
Cover and chill in the fridge for the night to ferment. This time could be shortened to 2 to 4 hours or skipped altogether, though the longer it ferments, the lighter and fluffier the pancakes will be.
In the morning - Remove the bowl from the fridge and whisk in the baking powder, bicarbonate of soda, salt, eggs and melted butter.
Preheat pancake griddle and grease.
Pour around ¼ cup of batter onto the hot, greased griddle and cook until the pancake starts to bubble on top.
Flip the pancake over and cook for 1 - 2 minutes before removing.