In a large bowl whisk the sponge ingredients together, let sit at room temperature for 1 hour until it doubles in size.
Add the batter ingredients to the sponge ingredients, mix till combined. Make sure to hang on to the that egg white, you’ll use it tomorrow. Cover and refrigerate the batter over night.
Let the batter sit out and come to room temperature, 1-2 hours.
In a clean bowl whisk the egg white to soft peaks and gently fold into the batter.
Add some butter to a large skillet on medium high heat, use a ladle to make small, very small, dollops of batter. Cook them just like pancakes, flip them when little bubbles form on the surface of the raw batter.
These do not have to be served piping hot, pile on a plate and cover with a towel while you make all of them. They can sit like this for up to an hour before you serve, it will take a little bit of time to make them, specially if you make them very small.