Gather your ingredients. Start by measuring out your sourdough discard into a large mixing bowl. Learn how to adapt your recipe based on how much starter discard you have in the scaling recipe section below.
Melt the butter over medium heat in the large skillet. Pour the butter into a glass liquid carafe to cool.
Turn off the skillet and set aside for cooking the crepes later.
Add the sugar, vanilla extract, pinches of salt, and eggs into the large mixing bowl. Whisk well until the eggs are completely whisked into the discard and the consistency is smooth.
Once the butter has cooled down to about 80 degrees F (27 degrees C), drizzle the melted butter slowly into the batter as you simultaneously whisk it in.
The batter should have a very thin, smooth with the consistency of heavy cream. If your batter is too thick, add a tablespoon of milk and whisk in. Repeat until you have the desired consistency.