Mix flour, sugar, and salt in a mixing bowl.

Add milk and whisk well.

Add sourdough starter and vanilla and whisk again until combined.

Add eggs and whisk well to combine.

Finally add melted butter and whisk very well to combine.

Cover or transfer to a jar and place in the refrigerator overnight.

When ready to make crepes, whisk in 2-4 tablespoons of water or milk to thin the batter.

Preheat a 9 inch cast iron or non-stick pan over medium-high heat. When skillet is hot, butter very lightly or spray lightly with cooking oil. Add 1/3 cup of crepe batter to the center of the pan and immediately swirl the pan in all directions to distribute the batter evenly to the edges. If your pan is smaller than 9 inches, you'll want to use a bit less batter.

Cook for about 1 minute on the first side before flipping and cooking for 30-60 more seconds. Transfer to a plate and repeat until all batter has been used. 

Serve warm with filling of choice. See blog post for lots of filling ideas and additional info.