In a bowl, put flour, cocoa powder and the pinch of salt.
Add the egg, vanilla extract and milk.
Whisk everything well.
Strain the mixture.
Pour in a measuring cup and cover with plastic wrap.
Let rest for at least 10 minutes.
Place a non stick small pan on medium low heat.
Put a very small amount of butter in the pan.
Use paper towel to clean the pan with butter.
Pour about 1/4 cup of the crêpe mixture on the pan.
Move the pan in a way to get the crepe mixture cover the bottom of the pan.
Let cook for 1 to 2 minutes per side.