Whisk all of the ingredients together to make a smooth batter. Allow the batter to sit in the refrigerator several hours before cooking.
You may need to add more milk at this point. You want the batter to be pourable, but not too liquid.
To cook, heat a non-stick skillet or crepe pan on medium heat until hot. Using a paper towel coat the bottom of the pan with a bit of butter. Pour in a scant 1/4 cup of batter (for about 9 inch crepes) and tilt and turn the pan to spread the batter evenly. Once the top of the crepe is just cooked, use a spatula to gently turn it and cook for 15 more seconds. You may have to adjust your heat to get the crepes just right - they should be lightly browned on both sides.
As you cook each crepe, stack and wrap them in a clean tea towel. This will keep them warm. Or you can rewarm them by wrapping in aluminum foil and warming in the oven.
Makes about 10 crepes.