Mix together the egg, sourdough starter, vanilla, oil, and milk in a large bowl.
In a small bowl whisk together the flour, baking powder, and salt.
Mix the dry ingredients into the wet ingredients.
If you are not going to ferment them overnight, go ahead and cook the pancakes. If you are going to ferment them overnight, cover the batter with cling wrap and ferment for 8-12 hours.
When it is time to cook them, heat a pan, I use cast iron, over medium heat. Grease with butter or coconut oil. Spoon batter onto the heated pan to the desired size.
Cook until all the bubbles pop, flip, and cook until golden on the other side.